System and method for a six-primary wide gamut color system

ABSTRACT

Systems and methods for a six-primary color system for display. A six-primary color system increases the number of primary colors available in a color system and color system equipment. Increasing the number of primary colors reduces metameric errors from viewer to viewer. The six-primary color system includes Red, Green, Blue, Cyan, Yellow, and Magenta primaries. The systems of the present invention maintain compatibility with existing color systems and equipment and provide systems for backwards compatibility with older color systems.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 16/887,807, filed May 29, 2020, which is a continuation-in-part of U.S. application Ser. No. 16/860,769, filed Apr. 28, 2020, which is a continuation-in-part of U.S. application Ser. No. 16/853,203, filed Apr. 20, 2020, which is a continuation-in-part of U.S. patent application Ser. No. 16/831,157, filed Mar. 26, 2020, which is a continuation of U.S. patent application Ser. No. 16/659,307, filed Oct. 21, 2019, now U.S. Pat. No. 10,607,527, which is related to and claims priority from U.S. Provisional Patent Application No. 62/876,878, filed Jul. 22, 2019, U.S. Provisional Patent Application No. 62/847,630, filed May 14, 2019, U.S. Provisional Patent Application No. 62/805,705, filed Feb. 14, 2019, and U.S. Provisional Patent Application No. 62/750,673, filed Oct. 25, 2018, each of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to color systems, and more specifically to a wide gamut color system with an increased number of primary colors.

2. Description of the Prior Art

It is generally known in the prior art to provide for an increased color gamut system within a display.

Prior art patent documents include the following:

U.S. Pat. No. 10,222,263 for RGB value calculation device by inventor Yasuyuki Shigezane, filed Feb. 6, 2017 and issued Mar. 5, 2019, is directed to a microcomputer that equally divides the circumference of an RGB circle into 6×n (n is an integer of 1 or more) parts, and calculates an RGB value of each divided color. (255, 0, 0) is stored as a reference RGB value of a reference color in a ROM in the microcomputer. The microcomputer converts the reference RGB value depending on an angular difference of the RGB circle between a designated color whose RGB value is to be found and the reference color, and assumes the converted RGB value as an RGB value of the designated color.

U.S. Pat. No. 9,373,305 for Semiconductor device, image processing system and program by inventor Hiorfumi Kawaguchi, filed May 29, 2015 and issued Jun. 21, 2016, is directed to an image process device including a display panel operable to provide an input interface for receiving an input of an adjustment value of at least a part of color attributes of each vertex of n axes (n is an integer equal to or greater than 3) serving as adjustment axes in an RGB color space, and an adjustment data generation unit operable to calculate the degree of influence indicative of a following index of each of the n-axis vertices, for each of the n axes, on a basis of distance between each of the n-axis vertices and a target point which is an arbitrary lattice point in the RGB color space, and operable to calculate adjusted coordinates of the target point in the RGB color space.

U.S. Publication No. 20130278993 for Color-mixing bi-primary color systems for displays by inventor Heikenfeld, et. al, filed Sep. 1, 2011 and published Oct. 24, 2013, is directed to a display pixel. The pixel includes first and second substrates arranged to define a channel. A fluid is located within the channel and includes a first colorant and a second colorant. The first colorant has a first charge and a color. The second colorant has a second charge that is opposite in polarity to the first charge and a color that is complimentary to the color of the first colorant. A first electrode, with a voltage source, is operably coupled to the fluid and configured to moving one or both of the first and second colorants within the fluid and alter at least one spectral property of the pixel.

U.S. Pat. No. 8,599,226 for Device and method of data conversion for wide gamut displays by inventor Ben-Chorin, et. al, filed Feb. 13, 2012 and issued Dec. 3, 2013, is directed to a method and system for converting color image data from a, for example, three-dimensional color space format to a format usable by an n-primary display, wherein n is greater than or equal to 3. The system may define a two-dimensional sub-space having a plurality of two-dimensional positions, each position representing a set of n primary color values and a third, scaleable coordinate value for generating an n-primary display input signal. Furthermore, the system may receive a three-dimensional color space input signal including out-of range pixel data not reproducible by a three-primary additive display, and may convert the data to side gamut color image pixel data suitable for driving the wide gamut color display.

U.S. Pat. No. 8,081,835 for Multiprimary color sub-pixel rendering with metameric filtering by inventor Elliot, et. al, filed Jul. 13, 2010 and issued Dec. 20, 2011, is directed to systems and methods of rendering image data to multiprimary displays that adjusts image data across metamers as herein disclosed. The metamer filtering may be based upon input image content and may optimize sub-pixel values to improve image rendering accuracy or perception. The optimizations may be made according to many possible desired effects. One embodiment comprises a display system comprising: a display, said display capable of selecting from a set of image data values, said set comprising at least one metamer; an input image data unit; a spatial frequency detection unit, said spatial frequency detection unit extracting a spatial frequency characteristic from said input image data; and a selection unit, said unit selecting image data from said metamer according to said spatial frequency characteristic.

U.S. Pat. No. 7,916,939 for High brightness wide gamut display by inventor Roth, et. al, filed Nov. 30, 2009 and issued Mar. 29, 2011, is directed to a device to produce a color image, the device including a color filtering arrangement to produce at least four colors, each color produced by a filter on a color filtering mechanism having a relative segment size, wherein the relative segment sizes of at least two of the primary colors differ.

U.S. Pat. No. 6,769,772 for Six color display apparatus having increased color gamut by inventor Roddy, et. al, filed Oct. 11, 2002 and issued Aug. 3, 2004, is directed to a display system for digital color images using six color light sources or two or more multicolor LED arrays or OLEDs to provide an expanded color gamut. Apparatus uses two or more spatial light modulators, which may be cycled between two or more color light sources or LED arrays to provide a six-color display output. Pairing of modulated colors using relative luminance helps to minimize flicker effects.

SUMMARY OF THE INVENTION

It is an object of this invention to provide an enhancement to the current RGB systems or a replacement for them.

In one embodiment, the present invention is a system for displaying a six primary color system, including a set of image data, wherein the set of image data is comprised of a first set of color channel data and a second set of color channel data, wherein the set of image data further includes a bit level, an image data converter, wherein the image data converter includes a digital interface, wherein the digital interface is operable to encode and decode the set of image data, at least one transfer function (TF) for processing the set of image data, a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable, at least one display device, wherein the at least one display device and the image data converter are in network communication, wherein the image data converter is operable to convert the bit level of the set of image data, thereby creating an updated bit level, wherein the image data converter is operable to convert the set of image data for display on the at least one display device, wherein once the set of image data has been converted by the image data converter for the at least one display device, the set of SDP parameters is modified based on the conversion, and wherein the at least one display device is operable to display a six-primary color system based on the set of image data, such that the SDP parameters indicate that the set of image data being displayed on the at least one display device is using a six-primary color system.

In another embodiment, the present invention is a system for displaying a six-primary color system, including a set of image data, wherein the set of image data includes a first set of color channel data and a second set of color channel data, wherein the set of image data includes a bit level, a magenta primary value, wherein the magenta primary value is derived from the set of image data, an image data converter, wherein the image data converter includes a digital interface, wherein the digital interface is operable to encode and decode the set of image data, at least one transfer function (TF) for processing the set of image data, a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable, at least one display device, wherein the at least one display device and the image data converter are in network communication, wherein the image data converter is operable to convert the bit level for the set of image data to a new bit level, wherein the at least one data converter is operable to convert the set of image data for display on the at least one display device, wherein once the set of image data has been converted for the at least one display device, the set of SDP parameters is modified based on the conversion, and wherein the at least one display device is operable to display a six-primary color system based on the set of image data, such that the SDP parameters indicate the magenta primary value and that the set of image data being displayed on the at least one display device is using a six-primary color system.

In yet another embodiment, the present invention is a system for displaying a set of image data using a six-primary color system, including a set of image data, wherein the set of image data includes a bit level, a magenta primary value, wherein the magenta primary value is derived from the set of image data, an image data converter, wherein the image data converter includes a digital interface, wherein the digital interface is operable to encode and decode the set of image data, at least one transfer function (TF) for processing the set of image data, a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable, at least one electronic luminance component, wherein the electronic luminance component is derived from the set of image data, at least one display device, wherein the at least one display device and the image data converter are in network communication, wherein the image data converter is operable to convert the set of image data to a new bit level, wherein the at least one image data converter is operable to convert the set of image data for display on the at least one display device, wherein once the set of image data has been converted for the at least one display device, the set of SDP parameters is modified based on the conversion, and wherein the at least one display device is operable to display a six-primary color system based on the set of image data, such that the SDP parameters indicate the magenta primary value, the at least one electronic luminance component, and that the set of image data being displayed on the at least one display device is using a six-primary color system.

These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings, as they support the claimed invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 illustrates color spectrum.

FIG. 2 illustrates an adaptive optics view of the mosaic of L (red), M (green), and S (blue) cones in four human subjects with normal color vision.

FIG. 3A illustrates the spectral output of an LCD display using a CCFL backlight and a simulation of what Viewer A is sensitive to.

FIG. 3B illustrates the spectral output of an LCD display using a CCFL backlight and a simulation of what Viewer B is sensitive to.

FIG. 4A illustrates a spectral output of a laser driven display using discrete RGB laser emitters and a simulation of what Viewer A is sensitive to, where the display is using an ITU-R BT.2020 gamut.

FIG. 4B illustrates a spectral output of a laser driven display using discrete RGB laser emitters and a simulation of what Viewer B is sensitive to, where the display is using an ITU-R BT.2020 gamut.

FIG. 5 illustrates how a display simulates color using the Commission on Illumination (CIE 1976) color space shown as L*a*b.

FIG. 6 illustrates a comparison of the ITU-R BT.2020 color gamut to the Pointer data set of real colors.

FIG. 7 illustrates a comparison of the ITU-R BT.709-6 color gamut to the Pointer data set of real colors.

FIG. 8 illustrates the CYM hue angles added to a legacy RGB color gamut based on equal saturation defined by ITU-R BT.709-6.

FIG. 9 illustrates a RGBCYM system based on the ITU-R BT.709-6 color saturation shown over the Pointer data set of real colors.

FIG. 10A illustrates a comparison of the overall gamut values between a six-primary system and an ITU-R BT.2020 system, with estimated differences between spectral displayed outputs.

FIG. 10B illustrates an RGBCYM system based on ITU-R BR 709 Color Saturation (6P-B).

FIG. 10C illustrates the ITU-R BR.2020 spectral recommendation.

FIG. 10D illustrates the ITU-R BT.2020 system. In one embodiment, the white point is a D60 white point

FIG. 11 illustrates a RGBCYM system based on ITU-R BT.709 color saturation compared to ITU-R BT.2020.

FIG. 12 illustrates a comparison between ITU-R BT.709, SMPTE RP431-2, and ITU-R BT.2020 color gamuts.

FIG. 13 illustrates the Pointer color data set with a six-primary color system based on SMPTE RP431-2 saturation and ITU-R BT.2020 superimposed.

FIG. 14 illustrates a RGBCYM system compared to a Sony S gamut, Arri AWG, and ACES APO.

FIG. 15 illustrates the workflow to use a six-primary color system using a new input transfer transform.

FIG. 16A illustrates a mosaic filter configuration using a magenta filter for the present invention.

FIG. 16B illustrates a mosaic filter configuration not using a magenta filter for the present invention.

FIG. 17 illustrates an expansion to the demuxing process to handle the placement of additional color elements.

FIG. 18 illustrates a signal inversion process in a single imager camera.

FIG. 19 illustrates a prism made up of three glass elements and two dichroic filters.

FIG. 20 illustrates a prism design for a six-imager camera for use in a six-primary color system.

FIG. 21 illustrates an embodiment of an encode and decode system for a six-primary color system.

FIG. 22 illustrates a sequential method where three color primaries are passed to the transport format as full bit level image data and inserted as normal.

FIG. 23 illustrates one embodiment of a six-primary color system encode using a 4:4:4 sampling method.

FIG. 24 illustrates one embodiment for a method to package six channels of primary information into the three standard primary channels used in current serial video standards by modifying bit numbers for a 12-bit SDI and a 10-bit SDI.

FIG. 25 illustrates a simplified diagram estimating perceived viewer sensation as code values define each hue angle.

FIG. 26 illustrates one embodiment for a method of stacking/encoding six-primary color information using a 4:4:4 video system.

FIG. 27 illustrates one embodiment for a method of unstacking/decoding six-primary color information using a 4:4:4 video system.

FIG. 28 illustrates one embodiment of a 4:4:4 decoder for a six-primary color system.

FIG. 29 illustrates an embodiment of the present invention for sending six primary colors to a standardized transport format.

FIG. 30 illustrates one embodiment of a decode process adding a pixel delay to the RGB data for realigning the channels to a common pixel timing.

FIG. 31 illustrates one embodiment of an encode process for 4:2:2 video for packaging five channels of information into the standard three-channel designs.

FIG. 32 illustrates one embodiment for a non-constant luminance encode for a six-primary color system.

FIG. 33 illustrates one embodiment of a packaging process for a six-primary color system.

FIG. 34 illustrates a 4:2:2 unstack process for a six-primary color system.

FIG. 35 illustrates one embodiment of a process to inversely quantize each individual color and pass the data through an electronic optical function transfer (EOTF) in a non-constant luminance system.

FIG. 36 illustrates one embodiment of a constant luminance encode for a six-primary color system.

FIG. 37 illustrates one embodiment of a constant luminance decode for a six-primary color system.

FIG. 38 illustrates one example of 4:2:2 non-constant luminance encoding. (illustrates one embodiment for channeling six-primary color system output into a standard SMPTE ST292 serial system.)

FIG. 39 illustrates one embodiment of a non-constant luminance decoding system.

FIG. 40 illustrates one embodiment of a 4:2:2 constant luminance encoding system.

FIG. 41 illustrates one embodiment of a 4:2:2 constant luminance decoding system.

FIG. 42 illustrates a raster encoding diagram of sample placements for a six-primary color system.

FIG. 43 illustrates one embodiment of the six-primary color unstack process in a 4:2:2 video system.

FIG. 44 illustrates one embodiment of mapping input to the six-primary color system unstack process.

FIG. 45 illustrates one embodiment of mapping the output of a six-primary color system decoder.

FIG. 46 illustrates one embodiment of mapping the RGB decode for a six-primary color system.

FIG. 47 illustrates one embodiment of six-primary color output using a non-constant luminance decoder.

FIG. 48 illustrates one embodiment of a legacy RGB process within a six-primary color system.

FIG. 49 illustrates one embodiment of an unstack system for a six-primary color system.

FIG. 50 illustrates one embodiment of a legacy RGB decoder for a six-primary, non-constant luminance system.

FIG. 51 illustrates one embodiment of a legacy RGB decoder for a six-primary, constant luminance system.

FIG. 52 illustrates one embodiment of a six-primary color system with output to a legacy RGB system.

FIG. 53 illustrates one embodiment of packing six-primary color system image data into an IC_(T)C_(P) (ITP) format.

FIG. 54 illustrates one embodiment of a six-primary color system converting RGBCYM image data into XYZ image data for an ITP format.

FIG. 55 illustrates one embodiment of six-primary color mapping with SMPTE ST424.

FIG. 56 illustrates one embodiment of a six-primary color system readout for a SMPTE ST424 standard.

FIG. 57 illustrates one embodiment for mapping RGBCYM data to the SMPTE ST2082 standard for a six-primary color system.

FIG. 58 illustrates one embodiment for mapping Y_(RGB) Y_(CYM) C_(R) C_(B) C_(C) C_(Y) data to the SMPTE ST2082 standard for a six-primary color system.

FIG. 59 illustrates one embodiment for mapping six-primary color system data using the SMPTE ST292 standard.

FIG. 60 illustrates one embodiment of the readout for a six-primary color system using the SMPTE ST292 standard.

FIG. 61 illustrates modifications to the SMPTE ST352 standards for a six-primary color system.

FIG. 62 illustrates modifications to the SMPTE ST2022 standard for a six-primary color system.

FIG. 63 illustrates a table of 4:4:4 sampling for a six-primary color system for a 10-bit video system.

FIG. 64 illustrates a table of 4:4:4 sampling for a six-primary color system for a 12-bit video system.

FIG. 65 illustrates sequence substitutions for 10-bit and 12-bit video in 4:2:2 sampling systems in a Y Cb Cr Cc Cy color space.

FIG. 66 illustrates sample placements of six-primary system components for a 4:2:2 sampling system image.

FIG. 67 illustrates sequence substitutions for 10-bit and 12-bit video in 4:2:0 sampling systems using a Y Cb Cr Cc Cy color space.

FIG. 68 illustrates sample placements of six-primary system components for a 4:2:0 sampling system image.

FIG. 69 illustrates modifications to SMPTE ST2110-20 for a 10-bit six-primary color system in 4:4:4 video.

FIG. 70 illustrates modifications to SMPTE ST2110-20 for a 12-bit six-primary color system in 4:4:4 video.

FIG. 71 illustrates modifications to SMPTE ST2110-20 for a 10-bit six primary color system in 4:2:2 video

FIG. 72 illustrates modifications to SMPTE ST2110-20 for a 12-bit six-primary color system in 4:2:0 video.

FIG. 73 illustrates a RGB sampling transmission for a 4:4:4 sampling system.

FIG. 74 illustrates a RGBCYM sampling transmission for a 4:4:4 sampling system.

FIG. 75 illustrates an example of System 2 to RGBCYM 4:4:4 transmission.

FIG. 76 illustrates a Y Cb Cr sampling transmission using a 4:2:2 sampling system.

FIG. 77 illustrates a Y Cr Cb Cc Cy sampling transmission using a 4:2:2 sampling system.

FIG. 78 illustrates an example of a System 2 to Y Cr Cb Cc Cy 4:2:2 Transmission as non-constant luminance.

FIG. 79 illustrates a Y Cb Cr sampling transmission using a 4:2:0 sampling system.

FIG. 80 illustrates a Y Cr Cb Cc Cy sampling transmission using a 4:2:0 sampling system.

FIG. 81 illustrates a dual stack LCD projection system for a six-primary color system.

FIG. 82 illustrates one embodiment of a single projector.

FIG. 83 illustrates a six-primary color system using a single projector and reciprocal mirrors.

FIG. 84 illustrates a dual stack DMD projection system for a six-primary color system.

FIG. 85 illustrates one embodiment of a single DMD projector solution.

FIG. 86 illustrates one embodiment of a color filter array for a six-primary color system with a white OLED monitor.

FIG. 87 illustrates one embodiment of an optical filter array for a six-primary color system with a white OLED monitor.

FIG. 88 illustrates one embodiment of a matrix of an LCD drive for a six-primary color system with a backlight illuminated LCD monitor.

FIG. 89 illustrates one embodiment of an optical filter array for a six-primary color system with a backlight illuminated LCD monitor.

FIG. 90 illustrates an array for a Quantum Dot (QD) display device.

FIG. 91 illustrates one embodiment of an array for a six-primary color system for use with a direct emissive assembled display.

FIG. 92 illustrates one embodiment of a six-primary color system in an emissive display that does not incorporate color filtered subpixels.

FIG. 93 illustrates one embodiment of an optical filter.

FIG. 94 illustrates another embodiment of an optical filter.

FIG. 95 illustrates one embodiment of a system encode and decode process using a dual link method.

FIG. 96 illustrates one embodiment of an encoding process using a dual link method.

FIG. 97 illustrates one embodiment of a decoding process using a dual link method.

FIG. 98 illustrates one embodiment of a new extended gamut system.

FIG. 99 illustrates another embodiment of a new extended gamut system.

FIG. 100 illustrates one embodiment of a multi-primary triad process using CIE-1931 color space.

FIG. 101 illustrates a table of Blue to Red line edge values between RGB and RMB triads.

FIG. 102 illustrates a YWV plot of a 6P system and an ACES 0 system.

FIG. 103 illustrates a table corresponding to chromaticity matrix values for a 6P system

FIG. 104 illustrates a gamut using 6P-B chromaticity values for an ACES-to-6P-to-ACES conversion process.

FIG. 105 illustrates a process to validate the ACES-to-6P-to-ACES conversion process according to one embodiment of the present invention.

FIG. 106 is a schematic diagram of an embodiment of the invention illustrating a computer system.

DETAILED DESCRIPTION

The present invention is generally directed to a six-primary color system.

In one embodiment, the present invention is a system for displaying a six primary color system, including a set of image data, wherein the set of image data is comprised of a first set of color channel data and a second set of color channel data, wherein the set of image data further includes a bit level, an image data converter, wherein the image data converter includes a digital interface, wherein the digital interface is operable to encode and decode the set of image data, at least one transfer function (TF) for processing the set of image data, a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable, at least one display device, wherein the at least one display device and the image data converter are in network communication, wherein the image data converter is operable to convert the bit level of the set of image data, thereby creating an updated bit level, wherein the image data converter is operable to convert the set of image data for display on the at least one display device, wherein once the set of image data has been converted by the image data converter for the at least one display device, the set of SDP parameters is modified based on the conversion, and wherein the at least one display device is operable to display a six-primary color system based on the set of image data, such that the SDP parameters indicate that the set of image data being displayed on the at least one display device is using a six-primary color system. In one embodiment, the first set of color channel data is a set of values for red (R), green (G), and blue (B) (collectively “RGB”) primaries and the second set of color channel data is a set of values for cyan (C), yellow (Y), and magenta (M) (collectively “CYM”) primaries. In one embodiment, the bit level of the set of image data is 12 bits, wherein the image data converter remaps the bit level to 11 bits using the at least one TF, wherein the output from the at least one TF includes the updated bit level, wherein the updated bit level is 12 bits. In one embodiment, the bit level of the set of image data is 10 bits, wherein the image data converter remaps the bit level to 9 bits using the at least one TF, wherein the output from the at least one TF includes the updated bit level, wherein the updated bit level is 10 bits. In another embodiment, the system includes a set of saturation data corresponding to the set of image data, wherein the saturation data is calculated using the first set of color channel data, the second set of color channel data, and an illuminant white point, wherein the illuminant white point is the Standard Illuminant D65 (D65) white point, wherein the saturation data is used to extend a set of hue angles for the first set of color channel data and the second set of color channel data, wherein extending the huge angles produces an updated set of image data with equal saturation values. In yet another embodiment, the first set of color channel data includes a first bit value defining black and a first bit value defining white, wherein the second set of color channel data includes a second bit value defining black and a second bit level defining white, wherein the TF is operable to redefine the first bit value defining black, the first bit level defining white, the second bit level defining black, and the second bit level defining white. In yet another embodiment, the set of SDP parameters is modified to include data corresponding to the first set of color channel data and the second set of color channel data, wherein the first set of color channel data is a set of values for RGB primaries and the second set of color channel data is a set of values for CYM primaries. In yet another embodiment, the digital interface encodes and decodes the set of image data using at least one color difference component, wherein the at least one color difference component is operable for up-sampling and/or down-sampling.

In another embodiment, the present invention is a system for displaying a six-primary color system, including a set of image data, wherein the set of image data includes a first set of color channel data and a second set of color channel data, wherein the set of image data includes a bit level, a magenta primary value, wherein the magenta primary value is derived from the set of image data, an image data converter, wherein the image data converter includes a digital interface, wherein the digital interface is operable to encode and decode the set of image data, at least one transfer function (TF) for processing the set of image data, a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable, at least one display device, wherein the at least one display device and the image data converter are in network communication, wherein the image data converter is operable to convert the bit level for the set of image data to a new bit level, wherein the at least one data converter is operable to convert the set of image data for display on the at least one display device, wherein once the set of image data has been converted for the at least one display device, the set of SDP parameters is modified based on the conversion, and wherein the at least one display device is operable to display a six-primary color system based on the set of image data, such that the SDP parameters indicate the magenta primary value and that the set of image data being displayed on the at least one display device is using a six-primary color system. In one embodiment, the first set of color channel data is a set of values for red (R), green (G), and blue (B) (collectively “RGB”) primaries and the second set of color channel data is a set of values for cyan (C), yellow (Y), and magenta (M) (collectively “CYM”) primaries, wherein the M primary value is calculated based on values for R and B from the first set of color channel data. In one embodiment, the first set of color channel data defines a first minimum color luminance and a first maximum color luminance, wherein the second set of color channel data defines a second minimum color luminance and a second maximum color luminance. In another embodiment, the at least one TF quantizes the bit level of the set of image data to a lower bit level, thereby creating an updated bit level for the set of image data. In another embodiment, a peak brightness and a minimum brightness are calculated for the first set of color channel data and the second set of color channel data. In another embodiment, the system includes a standardized transport format, wherein the standardized transport format is operable to receive the first set of image data and the second set of image data as a combined set of image data, wherein the combined set of image data has a combined bit level equal to the bit level for the set of image data. In yet another embodiment, the SDP parameters include the first set of color channel data, the second set of color channel data, mapping data for the set of image data, framerate data for the set of image data, a sampling standard for the set of image data, a flag indicator, an active picture size code, a timestamp for the set of image data, a clock frequency for the set of image data, a frame count for the set of image data, a scrambling indicator, and/or a video format indicator. In yet another embodiment, the system includes a set of saturation data corresponding to the set of image data, wherein the saturation data is calculated using the first set of color channel data, the second set of color channel data, and an illuminant white point, wherein the illuminant white point is the Standard Illuminant D60 (D60) white point. In yet another embodiment, the at least one TF is an EOTF. In yet another embodiment, the magenta primary value is not defined as a wavelength.

In yet another embodiment, the present invention is a system for displaying a set of image data using a six-primary color system, including a set of image data, wherein the set of image data includes a bit level, a magenta primary value, wherein the magenta primary value is derived from the set of image data, an image data converter, wherein the image data converter includes a digital interface, wherein the digital interface is operable to encode and decode the set of image data, at least one transfer function (TF) for processing the set of image data, a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable, at least one electronic luminance component, wherein the electronic luminance component is derived from the set of image data, at least one display device, wherein the at least one display device and the image data converter are in network communication, wherein the image data converter is operable to convert the set of image data to a new bit level, wherein the at least one image data converter is operable to convert the set of image data for display on the at least one display device, wherein once the set of image data has been converted for the at least one display device, the set of SDP parameters is modified based on the conversion, and wherein the at least one display device is operable to display a six-primary color system based on the set of image data, such that the SDP parameters indicate the magenta primary value, the at least one electronic luminance component, and that the set of image data being displayed on the at least one display device is using a six-primary color system. In one embodiment, the at least one electronic luminance component is not calculated within the at least one display. In one embodiment, the set of image data includes red (R), green (G), blue (B), cyan (C), yellow (Y), and magenta (M) color primary values, wherein the magenta primary value is calculated based on the R and B color primary values. In one embodiment, the at least one TF is an OOTF. In another embodiment, the system further includes a sampling system, wherein the sampling system is a 4:4:4 sampling system, wherein the sampling system includes a bit for black and a bit for white, wherein the bit for black and the bit for white are operable to redefined within the sampling system. In another embodiment, the bit level for the set of image data is 12 bits. In another embodiment, the bit level for the set of image data is 10 bits. In yet another embodiment, the image data converter encoding and decoding are based on the ITU-R BT.709 color space. In yet another embodiment, the image data converter encoding and decoding are based on the SMPTE RP431-2 color space. In yet another embodiment, the set of image data is converted by the image data converter in real-time and/or near real-time. In yet another embodiment, the digital interface includes payload identification (ID) metadata, wherein the payload ID metadata is operable to identify the set of image data as a six-primary color set of image data.

The present invention relates to color systems. A multitude of color systems are known, but they continue to suffer numerous issues. As imaging technology is moving forward, there has been a significant interest in expanding the range of colors that are replicated on electronic displays. Enhancements to the television system have expanded from the early CCIR 601 standard to ITU-R BT.709-6, to SMPTE RP431-2, and ITU-R BT.2020. Each one has increased the gamut of visible colors by expanding the distance from the reference white point to the position of the Red (R), Green (G), and Blue (B) color primaries (collectively known as “RGB”) in chromaticity space. While this approach works, it has several disadvantages. When implemented in content presentation, issues arise due to the technical methods used to expand the gamut of colors seen (typically using a more-narrow emissive spectrum) can result in increased viewer metameric errors and require increased power due to lower illumination source. These issues increase both capital and operational costs.

With the current available technologies, displays are limited in respect to their range of color and light output. There are many misconceptions regarding how viewers interpret the display output technically versus real-world sensations viewed with the human eye. The reason we see more than just the three emitting primary colors is because the eye combines the spectral wavelengths incident on it into the three bands. Humans interpret the radiant energy (spectrum and amplitude) from a display and process it so that an individual color is perceived. The display does not emit a color or a specific wavelength that directly relates to the sensation of color. It simply radiates energy at the same spectrum which humans sense as light and color. It is the observer who interprets this energy as color.

When the CIE 2° standard observer was established in 1931, common understanding of color sensation was that the eye used red, blue, and green cone receptors (James Maxwell & James Forbes 1855). Later with the Munsell vision model (Munsell 1915), Munsell described the vision system to include three separate components: luminance, hue, and saturation. Using RGB emitters or filters, these three primary colors are the components used to produce images on today's modern electronic displays.

There are three primary physical variables that affect sensation of color. These are the spectral distribution of radiant energy as it is absorbed into the retina, the sensitivity of the eye in relation to the intensity of light landing on the retinal pigment epithelium, and the distribution of cones within the retina. The distribution of cones (e.g., L cones, M cones, and S cones) varies considerably from person to person.

Enhancements in brightness have been accomplished through larger backlights or higher efficiency phosphors. Encoding of higher dynamic ranges is addressed using higher range, more perceptually uniform electro-optical transfer functions to support these enhancements to brightness technology, while wider color gamuts are produced by using narrow bandwidth emissions. Narrower bandwidth emitters result in the viewer experiencing higher color saturation. But there can be a disconnect between how saturation is produced and how it is controlled. What is believed to occur when changing saturation is that increasing color values of a color primary represents an increase to saturation. This is not true, as changing saturation requires the variance of a color primary spectral output as parametric. There are no variable spectrum displays available to date as the technology to do so has not been commercially developed, nor has the new infrastructure required to support this been discussed.

Instead, the method that a display changes for viewer color sensation is by changing color luminance. As data values increase, the color primary gets brighter. Changes to color saturation are accomplished by varying the brightness of all three primaries and taking advantage of the dominant color theory.

Expanding color primaries beyond RGB has been discussed before. There have been numerous designs of multi-primary displays. For example, SHARP has attempted this with their four-color QUATTRON TV systems by adding a yellow color primary and developing an algorithm to drive it. Another four primary color display was proposed by Matthew Brennesholtz which included an additional cyan primary, and a six primary display was described by Yan Xiong, Fei Deng, Shan Xu, and Sufang Gao of the School of Physics and Optoelectric Engineering at the Yangtze University Jingzhou China. In addition, AU OPTRONICS has developed a five primary display technology. SONY has also recently disclosed a camera design featuring RGBCMY (red, green, blue, cyan, magenta, and yellow) and RGBCMYW (red, green, blue cyan, magenta, yellow, and white) sensors.

Actual working displays have been shown publicly as far back as the late 1990's, including samples from Tokyo Polytechnic University, Nagoya City University, and Genoa Technologies. However, all of these systems are exclusive to their displays, and any additional color primary information is limited to the display's internal processing.

Additionally, the Visual Arts System for Archiving and Retrieval of Images (VASARI) project developed a colorimetric scanner system for direct digital imaging of paintings. The system provides more accurate coloring than conventional film, allowing it to replace film photography. Despite the project beginning in 1989, technical developments have continued. Additional information is available at https://www.southampton.ac.uk/˜km2/projs/vasari/ (last accessed Mar. 30, 2020), which is incorporated herein by reference in its entirety.

None of the prior art discloses developing additional color primary information outside of the display. Moreover, the system driving the display is often proprietary to the demonstration. In each of these executions, nothing in the workflow is included to acquire or generate additional color primary information. The development of a six-primary color system is not complete if the only part of the system that supports the added primaries is within the display itself.

Referring now to the drawings in general, the illustrations are for the purpose of describing one or more preferred embodiments of the invention and are not intended to limit the invention thereto.

FIG. 1 illustrates one example of a color spectrum. The color spectrum can be stated as a colorimetric measurement, indicating the presence of ten distinct colors, and a radiometric measurement, wherein there are ten combinations of three distinct spectra. Colors on the spectrum include, but are not limited to red (R), blue (B), green (G), cyan (C), yellow (Y), and magenta (M).

FIG. 2 illustrates an adaptive optics view of the mosaic of L cones (shown in red), M cones (shown in green), and S cones (shown in blue) in four human subjects with normal color vision. The ratio of S to L and M cones is constant but that of L to M cones varies from 1:2.7 (L:M) to 16.51:1 (L:M).

FIG. 3A and FIG. 3B illustrate spectral output of an LCD display using a cold cathode fluorescent lamp (CCFL) backlight and a simulation of what Viewer A and Viewer B are sensitive to, respectively. The display output has a fairly broad spectral distribution (white arrow), so as the viewer looks at the image, differences in viewer sensitivity can be covered by this wider spectral distribution output from the display. The colored arrows show that the majority of the spectrum output falls under the area of the viewer's sensitivity. This means that the viewer has more information available to judge what that color is and that fewer metamerism issues are present.

FIG. 4A and FIG. 4B illustrate spectral output of a laser driven display using discrete RGB laser emitters and a simulation of what each viewer is sensitive to, where the display is using an ITU-R BT.2020 gamut. As shown from the colored arrows, the level of sensitivity for each color primary emission crosses a very different level between the two viewers. Also illustrated by the purple arrows are large gaps in the output spectrum where no radiant energy is emitted. This results in the eye seeing less light for the same spectral peak amplitude. This results in greater color discrepancy from viewer-to-viewer.

FIG. 5 illustrates how a display simulates color using the Commission on Illumination (CIE 1976) color space shown as L*a*b (CIELAB). CIELAB color space is a color space defined by the International Commission on Illumination (CIE) in 1976. It expresses color as three values: L* for the lightness from black (0) to white (100), a* from green (−) to red (+), and b* from blue (−) to yellow (+). CIELAB was designed so that the same amount of numerical change in these values corresponds roughly to the same amount of visually perceived change. The CIELAB color space is typically used when graphics for print have to be converted from RGB to CMYK, as the CIELAB gamut includes both the gamuts of Red (R), Green (G), and Blue (B) (collectively RGB) and Cyan (C), Magenta (M), Yellow (Y), and Black (K) (collectively CMYK) color models. Because three parameters are measured, the space itself is a three-dimensional (3D) real number space, allowing for infinitely many possible colors. In practice, the space is mapped onto a 3D integer space for digital representation. Referring to FIG. 5, what an observer thinks when changing saturations is that increasing values of a color primary increase color saturation (assumption shown on left side of figure). While this is true, it is not practical. There are no variable spectrum displays available to date as the technology to do this has not been commercially developed. Neither has the new infrastructure required to support this even been discussed.

Color saturation increases are actually accomplished by increasing brightness of the brightest primary for a particular color and reducing brightness for the other two primaries. The limiting saturation of the display does not change.

FIG. 6 illustrates a comparison of the ITU-R BT.2020 color gamut to the Pointer data set of real colors. ITU-R BT.2020 was designed to make a maximum range of colors within an RGB space. To do this, the standard assigns its color primaries to the edge of the 1931 standard observer locus. In order to make this work, the color primaries are in effect single frequency emitters with center frequencies at 630 nm (Red), 532 nm (Green), and 467 nm (Blue). If viewed as CIE 1976 Yu′v′, this looks quite large and should have a maximum range of color. ITU-R BT.2020 completely covers all of Pointer's data set. This should also be the goal of a six primary system. However, the six primary system should use wide bandwidth spectral output to minimize any metamerism issues. ITU-R BT.2020 defines various aspects of ultra-high-definition television (UHDTV) with standard dynamic range (SDR) and wide color gamut (WCG), including picture resolutions, frame rates with progressive scan, bit depths, color primaries, RGB, luma-chroma color representations, chroma subsampling, and an opto-electronic transfer function. The ITU-R BT.2020 color space can reproduce colors that cannot be shown with ITU-R BT.709 (HDTV) color space. The RGB primaries used by ITU-R BT.2020 are equivalent to monochromatic light sources on the CIE 1931 spectral locus.

FIG. 7 illustrates a comparison of the ITU-R BT.709-6 color gamut to the Pointer data set of real-world surface colors. ITU-R BT.709-6 is the maximum gamut that can currently be displayed using the most broad standard spectral emission primaries, and thus minimizes metameric issues. FIG. 7 also shows that a significant portion of the Pointer data set is not covered by the ITU-R BT.709-6 standard. ITU-R BT.709 standardizes the format of high-definition television (HDTV), having a 16:9 (widescreen) aspect ratio. ITU-R BT.709 refers to HDTV systems having roughly two million luma samples per frame. ITU-R BT.709 has two parts. Part 1 codifies what are now referred to as 1035i30 and 1152i25 HDTV systems. The 1035i30 system is now obsolete, having been superseded by 1080i and 1080p square-sampled (“square-pixel”) systems. The 1152i25 system was used for experimental equipment and was never commercially deployed. Part 2 codifies current and prospective 1080i and 1080p systems with square sampling by defining a common image format (CIF) with picture parameters independent of the picture rate.

A six-primary color system offers enhancements to the current RGB systems. It extends current color gamuts to a wider usable color gamut than currently offered and minimizes metamerisms (i.e., everyone sees the same color). By doubling the number of primaries, and making the primaries wide spectrum rather than narrow, viewer metameric errors are reduced.

In one embodiment, the six-primary color system is based on the ITU-R BT.709-6 color system. The ITU-R BT.709-6 color system offers the least amount of metameric errors due to its limited gamut requirement. In addition, the ITU-R BT.709-6 color system makes use of wide spectral energies, resulting in a more consistent color sensation from viewer to viewer. A six-primary color system using the ITU-R BT.709-6 color system requires three additional primary colors: Cyan (C), Yellow (Y), and Magenta (M). It is important to match these additional color primaries to an equal saturation level and to be at complementary wavelengths to the original ITU-R BT.709-6 RGB and SMPTE RP431-2 RGB primary colors.

In addition, ITU-R BT.709-6 supports picture scanning characteristics including, but not limited to, an order of sample presentation in a scanned system, a total number of lines, field frequency, frame frequency, segment frequency, interlace ratio, picture rate (Hz), samples per full line, nominal analogue signal bandwidths (MHz), sampling frequency (MHz) for RGBY, and/or sampling frequency (MHz) for Cb Cr.

Saturation is defined between two coordinates, a white point and a color primary.

Saturation is calculated as: S _(uv)=13[u′−u′ _(n))²+(v′+v′ _(n))²]^(1/2) wherein u′ and v′ reference coordinate points in a chromaticity diagram. In one embodiment, the chromaticity diagram is the Commission on Illumination (CIE) 1976 u ‘v’ chromaticity diagram.

In one embodiment, the white point for image is defined as the CIE Standard Illuminant D65 (D65). D65 is a commonly used standard illuminant and is part of the D series illuminants that attempt to portray standard illumination conditions at open-air in different parts of the world. D65 corresponds roughly to the average midday light in Western and Northern Europe, comprised of both direct sunlight and the light diffused by a clear sky. As any standard illuminant is represented as a table of averaged spectrophotometric data, any light source which statistically has the same relative spectral power distribution (SPD) can be considered a D65 light source. The D65 white point is used for ITU-R BT.709. Alternatively, the white point is defined as a D60 white point. The D60 white point is used for SMPTE RP431, which is discussed infra.

Saturation values with a D65 white point are as follows: S _(Red)=3.3630315 S _(Green)=1.5477145 S _(Blue)=4.046013

The additional primaries for a six-primary color system using the ITU-R BT.709-6 color system are inverted and equidistant from the original RGB primaries. In order to accomplish this, a hue rotation is necessary. The hue rotation can be calculated as: h _(uv)=tan⁻¹(v*/u*)

Using the above hue rotation calculation, the following hue angles are produced: H _(Red)=167.823° H _(Green)=52.2849° H _(Blue)=85.8743° Extending the hue angles to the opposite side of the gamut locus, and assigning a CYM (S_(CYM)) primary set at an equal saturation value to an opposing color (e.g., cyan equal to red, yellow equal to blue, magenta equal to green) results in a balanced six-color primary system.

In one embodiment, the six-primary color system is based on the ITU-R BT.2020 color system. The ITU-R BT.2020 color system is the current standardized wide gamut system. This standard assigns its color primaries to the edge of the 1931 standard observer locus. In a six-primary color system using this standard, the color primaries are single frequency emitters with frequencies centered at 630 nm (Red), 532 nm (Green), and 467 nm (Blue). In another embodiment, the six-primary color system is based on the ITU-R BT.709 color system. In another embodiment, the six-primary color system is based a color system other than ITU-R BT.709 or ITU-R BT.2020.

FIG. 8 illustrates the ITU-R BT.709-6 color gamut with CYM hue angles added. In addition, a D65 white point is used for the additional hue angles. In another embodiment, the white point is a D60 white point.

FIG. 9 illustrates a RGBCYM system based on the ITU-R BT.709-6 color saturation (“6P-B”) shown over the Pointer data set of real colors. The D65 white point is indicated by the red triangle. This RGBCYM system covers six primary colors, with hue angles for Yellow, Cyan, and Magenta. The biggest difference between this primary set and the primary set of ITU-R BT.2020 is that the gamut shown as a six primary system is using a wide bandwidth set of primaries.

FIG. 10A illustrates a six primary sample spectrum. FIG. 10B illustrates an RGBCYM system based on ITU-R BT.709 Color Saturation (6P-B). FIG. 10C illustrates the ITU-R BT.2020 spectral recommendation. FIG. 10D illustrates the ITU-R BT.2020 system. In one embodiment, the white point is a D60 white point. In another embodiment, the white point is a D65 white point.

FIG. 11 illustrates a RGBCYM system based on ITU-R BT.709 color saturation compared to ITU-R BT.2020. While the ITU-R BT.2020 system covers a larger volume, the six-primary color system benefits from a more repeatable color sensation between viewers. This repeatability makes a six-primary color system advantageous over non six-primary color systems.

White Point Designation

With any three-primary color system, the white point is a separate consideration regardless of color gamut. This is true in that saturation, dominant wavelength, and complementary wavelength are defined between two coordinates, white point and color primary. In a six-primary color system, this becomes more complicated. Hue angles for CYM are provided as the inverse vector of RGB (180° hue angle). Therefore, saturation changes must be defined through a three-part coordinate system. Additionally, in order for the system to function correctly, the white point should lie on a line drawn between two inverted primary colors. Thus, selection of D65 for a SMPTE RP431-2 gamut will not track. The same is true if there is a need to use the SMPTE ST431-1 standard white point.

The Society of Motion Picture and Television Engineers (SMPTE) is a global professional association of engineers, technologists, and executives working in the media and entertainment industry. The SMPTE has more than 800 standards, recommended practices, and engineering guidelines for broadcast, filmmaking, digital cinema, audio recording, information technology (IT), and medical imaging.

Specific primary positions related to that white point are used to implement this change. Each set of primaries now have a direct corresponding white point that is no longer a variable. There are three white points normally used for production. These are D65, D60, and the white point designated in SMPTE ST431-1. In another embodiment, the system uses a P3D65 white point. The SMPTE standard white point does not have a CIE/ISO spectral description, only a coordinate designation. D65 is described in spectral terms in CIE/ISO 11664-2 and formally in ISO 10526-1991. D60 is derived by linear interpolation based on the D65 spectral standard as:

${x_{D60} = {{0.\text{244,063}} + {{0.0}9911\frac{10^{3}}{60}} + {2.967}}},{{8\frac{10^{6}}{60^{2}}} - {{4.6}07}},{0\frac{10^{9}}{60^{3}}},{y_{D60} = {{{- {3.0}}00x_{D60}^{2}} + {{2.8}70x_{D60}} - {{0.2}75}}}$

These two white points are designated as D65 for television production and D60 for film production. Thus, one separate set of color primaries is designated for each application and each system has one individual matrix solution. TABLE 1 is the color space for D65 white point, which assumes ITU-R BT.709 saturation. TABLE 2 is the color space for D60 white point, which uses SMPTE RP431-2 saturation.

TABLE 1 Color space for D65 white point Color u′ v′ λD White 0.1978 0.4683 — Red 0.4507 0.5229 610 nm Green 0.125 0.5625 552 nm Blue 0.1754 0.1579 464 nm Yellow 0.204 0.565 571 nm Cyan 0.100 0.446 491 nm Magenta 0.330 0.293 Combined red & blue

TABLE 2 Color space for D60 white point Color u′ v′ λD White 0.2010 0.4740 — Red 0.4964 0.5256 617 nm Green 0.0098 0.5777 543 nm Blue 0.1754 0.1579 464 nm Yellow 0.2078 0.5683 571 nm Cyan 0.0960 0.4540 492 nm Magenta 0.3520 0.3200 Combined red & blue

Super 6P

One of the advantages of ITU-R BT.2020 is that it can include all of the Pointer colors and that increasing primary saturation in a six-color primary design could also do this. However, extending the 6P gamut beyond SMPTE RP431-2 (“6P-C”) adds two problems. The first problem is the requirement to narrow the spectrum of the extended primaries. The second problem is the complexity of designing a backwards compatible system using color primaries that are not related to current standards. But in some cases, there may be a need to extend the gamut beyond 6P-C and avoid these problems. If the goal is to encompass Pointer's data set, then it is possible to keep most of the 6P-C system and only change the cyan color primary position. In one embodiment, the cyan color primary position is located so that the gamut edge encompasses all of Pointer's data set. In another embodiment, the cyan color primary position is a location that limits maximum saturation. With 6P-C, cyan is positioned as u′=0.096, v′=0.454. In one embodiment of Super 6P, cyan is moved to u′=0.075, v′=0.430. Advantageously, this creates a new gamut that covers Pointer's data set almost in its entirety as shown in FIG. 98.

In an alternative embodiment, the saturation is expanded on the same hue angle as 6P-C as shown in FIG. 99. Advantageously, this makes backward compatibility less complicated. However, this requires much more saturation (i.e., narrower spectra). In another embodiment of Super 6P, cyan is moved to u′=0.067, v′=0.449.

Adding Three More Color Primaries within SMPTE RP431-2 Spaces

In one embodiment, the system is designed using the saturation and hue design from SMPTE RP431-2 (“6P-C”). What results is a system where the saturation levels are equal to what is used for digital cinema. Both the color gamut and the white point require modification. Since the white point is changed from D65 to D60, the saturation values and hue angles change to the following: S _(RED)=3.90028 H _(RED)=170.160° S _(GREEN)=1.88941 H _(GREEN)=45.3515° S _(BLUE)=4.12608 H _(BLUE)=85.4272°

FIG. 12 illustrates a comparison between ITU-R BT.709, SMPTE RP431-2, and ITU-R BT.2020 color gamuts. The illustration uses a D60 white point value. In one embodiment, the six-primary color system uses a D65 white point value.

FIG. 13 illustrates the Pointer color data set with a six-primary color system based on SMPTE RP431-2 saturation and ITU-R BT.2020 superimposed. The red triangle is the white point, which is a D60 white point. In another embodiment, the white point is a D65 white point.

Transfer Functions

The system design minimizes limitations to use standard transfer functions for both encode and/or decode processes. Current practices used in standards include, but are not limited to, ITU-R BT.1886, ITU-R BT.2020, SMPTE ST274, SMPTE ST296, SMPTE ST2084, and ITU-R BT.2100. These standards are compatible with this system and require no modification.

Acquisition

The development of a six-primary color system is not practical if the only part of the system that supports the added primaries is within the display itself. There is a need for the ability to acquire, transport, and store images as a six-primary color system. One aspect that will support a six-primary color system is the camera.

In one embodiment, modifications are made to an existing wide gamut camera. In one embodiment, RAW images are converted from an existing camera to six channels. In one embodiment, optical modifications are made to a single imager camera by using new filters. In another embodiment, signal inversion in a single imager camera is performed. In another embodiment, modifications are made to a six-imager camera.

FIG. 14 illustrates a system in which modifications have been made to an existing wide gamut camera. The current large format single imager camera sensors generally have capability to capture all colors that can be seen by the human vision system, albeit with some error. This is done using wide bandpass optical filters combined with the design of the imager photoconductor. In this system, all six primary points are covered by most acquisition technologies. Since these cameras supporting RAW output are already in use, they can serve as entry points into six-primary color system workflows.

In one embodiment, the optical filter is an absorptive optical filter. Absorptive filters have a coating of different organic and inorganic materials that absorb certain wavelengths of light, thus allowing the desired wavelengths to pass through. Since they absorb light energy, the temperature of these filters increases during operation. Absorptive filters are simple filters and are added to plastics to make less-costly filters than glass-based counterparts. The operation of absorptive filters does not depend on the angle of the incident light but on the properties of the material that makes up the filter.

In one embodiment, the optical filter is a dichroic filter. Dichroic filters consist of a series of optical coatings with precise thicknesses that are designed to reflect unwanted wavelengths and transmit the desired wavelength range. This is achieved by causing the desired wavelengths to interfere constructively on the transmission side of the filter, while other wavelengths interfere constructively on the reflection side of the filter.

In one embodiment, the optical filter is a short pass filter. Short pass filters allow shorter wavelengths than the cut-off wavelength to pass through, while it attenuates longer wavelengths. In one embodiment, the optical filter is a long pass filter. Long pass filters transmit longer wavelengths than the cut-on wavelength while blocking shorter wavelengths. In another embodiment, the optical filter is a band pass filter. Band pass filters let a particular range, or “band”, of wavelengths to go through, but attenuate all wavelengths around the band. In another embodiment, the optical filter is a multi-bandpass filter. In another embodiment, the optical filter is a multi-band dichroic beam splitter.

In one embodiment, the optical filter is a neutral density (ND) filter. ND filters are used in imaging and laser applications where excessive light can be damaging to camera sensors or other optical components. ND filters also prevent excessive light from causing inaccurate results in photometer applications.

In another embodiment, the optical filter is a machine vision filter. Machine vision filters are designed to improve image quality and contrast in imaging and other machine vision applications. Machine vision filters are used to increase or decrease color temperature, block unwanted ultraviolet or infrared light, reduce overall light transmittance, and transmit light of a specific polarization state.

In another embodiment, the optical filter is a notch filter. Notch filters are used in spectroscopy, confocal and multi-photon microscopy, laser-based fluorescence instrumentation, and other life science applications. Notch filters are filters that selectively reject a portion of the spectrum, while transmitting all other overall wavelengths.

FIG. 15 illustrates the workflow to use a six-primary color system using a new input transfer transform. This new input transfer transform maps the full RAW signals down to six-primary color signals. In one embodiment, RAW data captured from a wide gamut camera is received by an output transform, wherein the output transform maps the RAW data signals down to six-primary color signals.

FIG. 16A and FIG. 16B illustrate the use of two mosaic filter configurations of the present invention. In one embodiment, a Bayer pattern optical filter modified using a magenta filter is used. In another embodiment, a Bayer pattern optical filter not using a magenta filter is used, wherein the magenta element will be calculated later in the process by a serial data decoder. Difference in size of the yellow and green elements can be used to increase camera sensitivity.

FIG. 17 illustrates an expansion to the demuxing process to handle the placement of additional color elements. The camera demuxing process handles placement of the additional color elements by changing the imager timing generator and modifying demuxing switching at the imager output. Timing involves a simple sequence based on which color exited the imager and switching to the correct color processing path.

TABLE 3 compares the number of pixels required for different systems.

TABLE 3 Native Sub Bayer Sub System H Resolution V Resolution Pixel Count PixelCount 2K RGB 2048 1080  6,635,520  4,804,608 2K RGBCY 2048 1080 11,059,200  8,007,680 2K RGBCYM 2048 1080 12,509,184  9,609,216 4K RGB 4096 2160 26,542,080 19,906,560 4K RGBCY 4096 2160 44,236,800 33,177,600 4K RGBCYM 4096 2160 53,084,160 39,813,120

Signal Inversion in a Single Imager Camera

FIG. 18 illustrates a signal inversion process in a single imager camera. In some applications, the use of a low-cost, low-weight, and/or smaller size camera is required. Devices included in these categories include, but are not limited to, home movies, a cell phone, a tablet computing device, and/or a remote camera. These applications have limits which do not support high-quality optics or processing. In one embodiment, a six-primary color system for these applications inverts the RGB signals, which become the CYM color components. In such an embodiment, all color components have equal saturation values and 180° hue angles. Issues with gamma tracking and white point designation are eliminated.

Six Imager Camera

In one embodiment, a device in network communication with multiple sensors is used. Situations requiring a device in network communication with multiple sensors include, but are not limited to, recording quick movements within an image, high-speed photography, and/or recording and/or capturing live events. The main component of such a system is a glass prism which distributes images from the lens to each sensor.

FIG. 19 illustrates a prism made up of three glass elements and two dichroic filters. In one embodiment, the glass prism is comprised of three glass elements and two dichroic filters. In one embodiment, the glass prism is comprised of three glass elements, two dichroic filters, and at least one trim filter, wherein the at least one trim filter is mounted in front of each sensor. TABLE 4 lists filters and operations for each filter as shown in FIG. 19.

TABLE 4 Filter Operation F1 Reflect and reject blue F2 Reflect and reject red F3 Trim red component F4 Trim green component F5 Trim blue component

FIG. 20 illustrates a new prism design for a six-primary color system. The optics distribute six-primary color components without distortion and/or mirror artifacts. Reflections and/or flare within the glass elements are minimized, and light is passed through the prism more efficiently than a traditional three-primary color system. The delay of light passing through the new optical block is equal between color paths, minimizing any group delays. In one embodiment, the main distribution optics is composed of a beam splitter cross prism. Faces at each junction in the cube are half-mirrored to direct the image to at least three outside flats.

Mounted to each of the at least three outside flats are a set of prisms which, used in combination with at least one optical filter, distribute light to the correct sensor. Sensors are mounted to the output of the appropriate prism face. With this design, a full image is distributed to all six sensors. Three filters (F1, F5, and F9) are used to reject any part of the spectrum not used by the related sensors. These are fairly wide in that each passes about ⅓ of the visual spectrum. Rejection filters (F2, F6, and F10) are used to split off the secondary color from the adjacent color primary. Trim filters (F3, F4, F7, F8, F11, and F12) are placed in front of each sensor to tune the spectrum for the correct response. TABLE 5 lists filters, colors, start, and stop for each filter as shown in FIG. 20.

TABLE 5 Filter Color Start Stop F1 R-Y 630 nm 540 nm F2 Y reject F3 R Trim 620 nm 600 nm F4 Y Trim 595 nm 545 nm F5 G-C 600 nm 470 nm F6 Cyan reject F7 G Trim 580 nm 540 nm F8 C Trim 535 nm 475 nm F9 M-B 510 nm 380 nm F10 Magenta reject F11 B Trim 500 nm 435 nm F12 M Trim 445 nm 395 nm

In one embodiment, the set of prisms mounted to each of the at least three outside flats are a set of dichroic prisms. In another embodiment, the set of prisms mounted to each of the at least three outside flats are a set of trichroic prisms.

Packaging and Mapping Six Color Primaries

In one embodiment, the six-primary color system is compatible with legacy systems. A backwards compatible six-primary color system is defined by a sampling method. In one embodiment, the sampling method is 4:4:4. In one embodiment, the sampling method is 4:2:2. In another embodiment, the sampling method is 4:2:0. In one embodiment of a backwards compatible six-primary color system, new encode and decode systems are divided into the steps of performing base encoding and digitization, image data stacking, mapping into the standard data transport, readout, unstacking, and image decoding (“System 1”). System 1 combines opposing color primaries within three standard transport channels and identifies them by their code value. In one embodiment of a backwards compatible six-primary color system, the processes are analog processes. In another embodiment of a backwards compatible six-primary color system, the processes are digital processes.

In one embodiment, the sampling method for a six-primary color system is a 4:4:4 sampling method. Black and white bits are redefined. Putting black at midlevel within each data word allows the addition of CYM color data.

FIG. 21 illustrates an embodiment of an encode and decode system for a six-primary color system. In one embodiment, the six-primary color system encode and decode system is divided into a base encoder and digitation, image data stacking, mapping into the standard data transport, readout, unstack, and finally image decoding (“System 1”). The method of this system combines opposing color primaries within the three standard transport channels and identifies them by their code value. In one embodiment, the encode and decode for a six-primary color system are analog-based. In another embodiment, the encode and decode for a six-primary color system are digital-based.

FIG. 22 illustrates a sequential method where three color primaries are passed to the transport format as full bit level image data and inserted as normal (“System 2”). The three additional channels are delayed by one pixel and then placed into the transport instead of the first colors. This method is useful in situations where quantizing artifacts is critical to image performance. In one embodiment, this system is comprised of six primaries (RGBCYM), a method to delay the CYM colors for injection, image resolution identification to all for pixel count synchronization, start of video identification, RGB delay, and for YCCCCC systems, logic to select the dominant color primary.

Six-Primary Color Encode Using a 4:4:4 Sampling Method

FIG. 23 illustrates one embodiment of a six-primary color system encode using a 4:4:4 sampling method.

Current serial digital transport systems support 12 bits. Remapping six color components to a 12-bit stream is accomplished by lowering the bit limit to 11 bits (values 0 to 2047) for 12-bit serial systems or 9 bits (values 0 to 512) for 10-bit serial systems. This process is accomplished by processing RGBCYM video information through a standard Optical Electronic Transfer Function (OETF) (e.g., ITU-R BT.709-6), digitizing the video information as four samples per pixel, and quantizing the video information as 11-bit or 9-bit.

In another embodiment, the RGBCYM video information is processed through a standard Optical Optical Transfer Function (OOTF). In yet another embodiment, the RGBCYM video information is processed through a Transfer Function (TF) other than OETF or OOTF. TFs consist of two components, a Modulation Transfer Function (MTF) and a Phase Transfer Function (PTF). The MTF is a measure of the ability of an optical system to transfer various levels of detail from object to image. In one embodiment, performance is measured in terms of contrast (degrees of gray), or of modulation, produced for a perfect source of that detail level. The PTF is a measure of the relative phase in the image(s) as a function of frequency. A relative phase change of 180°, for example, indicates that black and white in the image are reversed. This phenomenon occurs when the TF becomes negative.

There are several methods for measuring MTF. In one embodiment, MTF is measured using discrete frequency generation. In one embodiment, MTF is measured using continuous frequency generation. In another embodiment, MTF is measured using image scanning. In another embodiment, MTF is measured using waveform analysis.

In one embodiment, the six-primary color system is for a 12-bit serial system. Current practices normally set black at bit value 0 and white at bit value 4095, for 12-bit video. In order to package six colors into the existing three-serial streams, the bit defining black is moved to bit value 2048. Thus, the new encode has RGB values starting at bit value 2048 for black and bit value 4095 for white and CYM values starting at bit value 2047 for black and bit value 0 as white. In another embodiment, the six-primary color system is for a 10-bit serial system.

FIG. 24 illustrates one embodiment for a method to package six channels of primary information into the three standard primary channels used in current serial video standards by modifying bit numbers for a 12-bit SDI and a 10-bit SDI. FIG. 25 illustrates a simplified diagram estimating perceived viewer sensation as code values define each hue angle. TABLE 6 and TABLE 7 list bit assignments for computer, production, and broadcast for a 12-bit system and a 10-bit system, respectively.

TABLE 6 12-Bit Assignments Computer Production Broadcast RGB CYM RGB CYM RGB CYM Peak Brightness 4095 0 4076 16 3839 256 Minimum Brightness 2048 2047 2052 2032 2304 1792

TABLE 7 10-Bit Assignments Computer Production Broadcast RGB CYM RGB CYM RGB CYM Peak Brightness 1023 0 1019 4 940 64 Minimum Brightness 512 511 516 508 576 448

In one embodiment, the OETF process is ITU-R BT.709-6. In one embodiment, the OETF process is ITU-R BT.709-5. In another embodiment, the OETF process is ITU-R BT.709-4. In yet another embodiment, the OETF process is ITU-R BT.709-3. In yet another embodiment, the OETF process is ITU-R BT.709-2. In yet another embodiment, the OETF process is ITU-R BT.709-1.

In one embodiment, the encoder is a non-constant luminance encoder. In another embodiment, the encoder is a constant luminance encoder.

Six-Primary Color Packing/Stacking Using a 4:4:4 Sampling Method

FIG. 26 illustrates one embodiment for a method of stacking/encoding six-primary color information using a 4:4:4 video system. Image data must be assembled according the serial system used. This is not a conversion process, but instead is a packing/stacking process. In one embodiment, the packing/stacking process is for a six-primary color system using a 4:4:4 sampling method.

FIG. 27 illustrates one embodiment for a method of unstacking/decoding six-primary color information using a 4:4:4 video system. In one embodiment, the RGB channels and the CYM channels are combined into one 12-bit word and sent to a standardized transport format. In one embodiment, the standardized transport format is SMPTE ST424 SDI. In one embodiment, the decode is for a non-constant luminance, six-primary color system. In another embodiment, the decode is for a constant luminance, six-primary color system. In yet another embodiment, an electronic optical transfer function (EOTF) (e.g., ITU-R BT.1886) coverts image data back to linear for display. FIG. 28 illustrates one embodiment of a 4:4:4 decoder.

System 2 uses sequential mapping to the standard transport format, so it includes a delay for the CYM data. The CYM data is recovered in the decoder by delaying the RGB data. Since there is no stacking process, the full bit level video can be transported. For displays that are using optical filtering, this RGB delay could be removed and the process of mapping image data to the correct filter could be eliminated by assuming this delay with placement of the optical filter and the use of sequential filter colors.

Two methods can be used based on the type of optical filter used. Since this system is operating on a horizontal pixel sequence, some vertical compensation is required. This can be either as a line double repeat using the same RGBCYM data to fill the following line as shown in FIG. 93, or could be separated as RGB on line one and CYM on line two as shown in FIG. 94.

FIG. 29 illustrates an embodiment of the present invention for sending six primary colors to a standardized transport format using a 4:4:4 encoder according to System 2. Encoding is straight forward with a path for RGB sent directly to the transport format. RGB data is mapped to each even numbered data segment in the transport. CYM data is mapped to each odd numbered segment. Because different resolutions are used in all of the standardized transport formats, there must be identification for what they are so that the start of each horizontal line and horizontal pixel count can be identified to time the RGB/CYM mapping to the transport. The identification is the same as currently used in each standardized transport function. TABLE 8, TABLE 9, TABLE 10, and TABLE 11 list 16-bit assignments, 12-bit assignments, 10-bit assignments, and 8-bit assignments, respectively.

TABLE 8 16-Bit Assignments Computer Production RGB CYM RGB CYM Peak Brightness 65536 65536 65216 65216 Minimum Brightness 0 0 256 256

TABLE 9 12-Bit Assignments Computer Production Broadcast RGB CYM RGB CYM RGB CYM Peak Brightness 4095 4095 4076 4076 3839 3839 Minimum Brightness 0 0 16 16 256 256

TABLE 10 10-Bit Assignments Computer Production Broadcast RGB CYM RGB CYM RGB CYM Peak Brightness 1023 1023 1019 1019 940 940 Minimum Brightness 0 0 4 4 64 64

TABLE 11 8-Bit Assignments Computer Production Broadcast RGB CYM RGB CYM RGB CYM Peak Brightness 255 255 254 254 235 235 Minimum Brightness 0 0 1 1 16 16

The decode adds a pixel delay to the RGB data to realign the channels to a common pixel timing. EOTF is applied and the output is sent to the next device in the system. Metadata based on the standardized transport format is used to identify the format and image resolution so that the unpacking from the transport can be synchronized. FIG. 30 shows one embodiment of a decoding with a pixel delay.

In one embodiment, the decoding is 4:4:4 decoding. With this method, the six-primary color decoder is in the signal path, where 11-bit values for RGB are arranged above bit value 2048, while CYM levels are arranged below bit value 2047 as 11-bit. If the same data set is sent to a display and/or process that is not operable for six-primary color processing, the image data is assumed as black at bit value 0 as a full 12-bit word. Decoding begins by tapping image data prior to the unstacking process.

Six-Primary Color Encode Using a 4:2:2 Sampling Method

In one embodiment, the packing/stacking process is for a six-primary color system using a 4:2:2 sampling method. In order to fit the new six-primary color system into a lower bandwidth serial system, while maintaining backwards compatibility, the standard method of converting from RGBCYM to a luminance and a set of color difference signals requires the addition of at least one new image designator.

In order for the system to package all of the image while supporting both six-primary and legacy displays, an electronic luminance component (Y) must be derived. The first component is: E′_(Y) ₆ . It can be described as: E′ _(Y) ₆ ₆=0.1063E′ _(red)+0.23195E′ _(Yellow)+0.3576E′ _(Green)+0.19685E′ _(Cyan)+0.0361E′ _(Blue)+0.0712E′ _(Magenta)

Critical to getting back to legacy display compatibility, value E′_(-Y) is described as: E′ _(−Y) =E′ _(Y) ₆ −(E′ _(Cyan) +E′ _(Yellow) +E′ _(Magenta))

In addition, at least two new color components are disclosed. These are designated as Cc and Cy components. The at least two new color components include a method to compensate for luminance and enable the system to function with older Y Cb Cr infrastructures. In one embodiment, adjustments are made to Cb and Cr in a Y Cb Cr infrastructure since the related level of luminance is operable for division over more components. These new components are as follows:

${E_{CR}^{\prime} = \frac{\left( {E_{R}^{\prime} - E_{Y_{6}}^{\prime}} \right)}{1.7874}},{E_{CB}^{\prime} = \frac{\left( {E_{B}^{\prime} - E_{Y_{6}}^{\prime}} \right)}{1.9278}},{E_{CC}^{\prime} = \frac{\left( {E_{C}^{\prime} - E_{Y_{6}}^{\prime}} \right)}{1.6063}},{E_{CY}^{\prime} = \frac{\left( {E_{Y}^{\prime} - E_{Y_{6}}^{\prime}} \right)}{1.5361}}$

Within such a system, it is not possible to define magenta as a wavelength. This is because the green vector in CIE 1976 passes into, and beyond, the CIE designated purple line. Magenta is a sum of blue and red. Thus, in one embodiment, magenta is resolved as a calculation, not as optical data. In one embodiment, both the camera side and the monitor side of the system use magenta filters. In this case, if magenta were defined as a wavelength, it would not land at the point described. Instead, magenta would appear as a very deep blue which would include a narrow bandwidth primary, resulting in metameric issues from using narrow spectral components. In one embodiment, magenta as an integer value is resolved using the following equation:

$M_{INT} = \left\lbrack \frac{\frac{B_{INT}}{2} + \frac{R_{INT}}{2}}{2} \right\rbrack$

The above equation assists in maintaining the fidelity of a magenta value while minimizing any metameric errors. This is advantageous over prior art, where magenta appears instead as a deep blue instead of the intended primary color value.

Six-Primary Non-Constant Luminance Encode Using a 4:2:2 Sampling Method

In one embodiment, the six-primary color system using a non-constant luminance encode for use with a 4:2:2 sampling method. Current practices use a non-constant luminance path design, which is found in all the video systems currently deployed. FIG. 31 illustrates one embodiment of an encode process for 4:2:2 video for packaging five channels of information into the standard three-channel designs. For 4:2:2, a similar method to the 4:4:4 system is used to package five channels of information into the standard three-channel designs used in current serial video standards. FIG. 31 illustrates 12-bit SDI and 10-bit SDI encoding for a 4:2:2 system. TABLE 12 and TABLE 13 list bit assignments for a 12-bit and 10-bit system, respectively.

TABLE 12 12-Bit Assignments Computer Production Broadcast EY₆ EC_(R), EC_(B) EC_(C), EC_(Y) EY₆ EC_(R), EC_(B) EC_(C), EC_(Y) EY₆ EC_(R), EC_(B) EC_(C), EC_(Y) Peak 4095 4095 0 4076 4076 16 3839 3839 256 Brightness Minimum 0 2048 2047 16 2052 2032 256 2304 1792 Brightness

TABLE 13 10-Bit Assignments Computer Production Broadcast EY₆ EC_(R), EC_(B) EC_(C), EC_(Y) EY₆ EC_(R), EC_(B) EC_(C), EC_(Y) EY₆ EC_(R), EC_(B) EC_(C), EC_(Y) Peak 1023 1023 0 1019 1019 4 940 940 64 Brightness Minimum 0 512 511 4 516 508 64 576 448 Brightness

FIG. 32 illustrates one embodiment for a non-constant luminance encoding process for a six-primary color system. The design of this process is similar to the designs used in current RGB systems. Input video is sent to the Optical Electronic Transfer Function (OETF) process and then to the E_(Y) ₆ encoder. The output of this encoder includes all of the image detail information. In one embodiment, all of the image detail information is output as a monochrome image.

The output is then subtracted from E′_(R), E′_(B), E′_(C), and E′_(Y) to make the following color difference components: E′ _(CR) ,E′ _(CB) ,E′ _(CC) ,E′ _(CY) These components are then half sampled (×2) while E′_(T) ₆ is fully sampled (×4).

FIG. 33 illustrates one embodiment of a packaging process for a six-primary color system. These components are then sent to the packing/stacking process. Components E′_(CY-INT) and E′_(CC-INT) are inverted so that bit 0 now defines peak luminance for the corresponding component. In one embodiment, this is the same packaging process performed with the 4:4:4 sampling method design, resulting in two 11-bit components combining into one 12-bit component.

Six-Primary Non-Constant Luminance Decode Using a 4:2:2 Sampling Method

FIG. 34 illustrates a 4:2:2 unstack process for a six-primary color system. In one embodiment, the image data is extracted from the serial format through the normal processes as defined by the serial data format standard. In another embodiment, the serial data format standard uses a 4:2:2 sampling structure. In yet another embodiment, the serial data format standard is SMPTE ST292. The color difference components are separated and formatted back to valid 11-bit data. Components E′_(CY-INT) and E′_(CC-INT) are inverted so that bit value 2047 defines peak color luminance.

FIG. 35 illustrates one embodiment of a process to inversely quantize each individual color and pass the data through an electronic optical function transfer (EOTF) in a non-constant luminance system. The individual color components, as well as E′_(Y) ₆ _(-INT), are inversely quantized and summed to breakout each individual color. Magenta is then calculated and E′_(Y) ₆ _(-INT) is combined with these colors to resolve green. These calculations then go back through an Electronic Optical Transfer Function (EOTF) process to output the six-primary color system.

In one embodiment, the decoding is 4:2:2 decoding. This decode follows the same principles as the 4:4:4 decoder. However, in 4:2:2 decoding, a luminance channel is used instead of discrete color channels. Here, image data is still taken prior to unstack from the E′_(CB-INT)+E′_(CY-INT) and E′_(CR-INT)+E′_(CC-INT) channels. With a 4:2:2 decoder, a new component, called E′_(-Y), is used to subtract the luminance levels that are present from the CYM channels from the E′_(CB-INT)+E′_(CY-INT) and E′_(CR-INT)+E′_(CC-INT) components. The resulting output is now the R and B image components of the EOTF process. E′_(-Y) is also sent to the G matrix to convert the luminance and color difference components to a green output. Thus, R′G′B′ is input to the EOTF process and output as G_(RGB), R_(RGB), and B_(RGB). In another embodiment, the decoder is a legacy RGB decoder for non-constant luminance systems.

In one embodiment, the standard is SMPTE ST292. In one embodiment, the standard is SMPTE RP431-2. In one embodiment, the standard is ITU-R BT.2020. In another embodiment, the standard is SMPTE RP431-1. In another embodiment, the standard is ITU-R BT.1886. In another embodiment, the standard is SMPTE ST274. In another embodiment, the standard is SMPTE ST296. In another embodiment, the standard is SMPTE ST2084. In yet another embodiment, the standard is ITU-R BT.2100. In yet another embodiment, the standard is SMPTE ST424. In yet another embodiment, the standard is SMPTE ST425. In yet another embodiment, the standard is SMPTE ST2110.

Six-Primary Constant Luminance Decode Using a 4:2:2 Sampling Method

FIG. 36 illustrates one embodiment of a constant luminance encode for a six-primary color system. FIG. 37 illustrates one embodiment of a constant luminance decode for a six-primary color system. The process for constant luminance encode and decode are very similar.

The main difference being that the management of E_(Y) ₆ is linear. The encode and decode processes stack into the standard serial data streams in the same way as is present in a non-constant luminance, six-primary color system. In one embodiment, the stacker design is the same as with the non-constant luminance system.

System 2 operation is using a sequential method of mapping to the standard transport instead of the method in System 1 where pixel data is combined to two color primaries in one data set as an 11-bit word. The advantage of System 1 is that there is no change to the standard transport. The advantage of System 2 is that full bit level video can be transported, but at double the normal data rate.

The difference between the systems is the use of two Y channels in System 2. Y_(RGB) and Y_(CYM) are used to define the luminance value for RGB as one group and CYM for the other.

FIG. 38 illustrates one example of 4:2:2 non-constant luminance encoding. Because the RGB and CYM components are mapped at different time intervals, there is no requirement for a stacking process and data is fed directly to the transport format. The development of the separate color difference components is identical to System 1.

The encoder for System 2 takes the formatted color components in the same way as System 1. Two matrices are used to build two luminance channels. Y_(RGB) contains the luminance value for the RGB color primaries. Y_(CYM) contains the luminance value for the CYM color primaries. A set of delays are used to sequence the proper channel for Y_(RGB), Y_(CMY), and the RBCY channels. This sequences Y_(RGB), CR, and CC channels into the even segments of the standardized transport and Y_(CMY), CB, and CY into the odd numbered segments. Since there is no combining color primary channels, full bit levels can be used limited only by the design of the standardized transport method. In addition, for use in matrix driven displays, there is no change to the input processing and only the method of outputting the correct color is required if the filtering or emissive subpixel is also placed sequentially.

Timing for the sequence is calculated by the source format descriptor which then flags the start of video and sets the pixel timing.

FIG. 39 illustrates one embodiment of a non-constant luminance decoding system. Decoding uses timing synchronization from the format descriptor and start of video flags that are included in the payload ID, SDP, or EDID tables. This starts the pixel clock for each horizontal line of identify which set of components are routed to the proper part of the decoder. A pixel delay is used to realign the color primarily data of each subpixel. Y_(RGB) and Y_(C)MY are combined to assemble a new Y₆ component which is used to decode the CR, CB, CC, CY, and CM components into RGBCYM.

The constant luminance system is not different from the non-constant luminance system in regard to operation. The difference is that the luminance calculation is done as a linear function instead of including the OOTF. FIG. 40 illustrates one embodiment of a 4:2:2 constant luminance encoding system. FIG. 41 illustrates one embodiment of a 4:2:2 constant luminance decoding system.

Six-Primary Color System Using a 4:2:0 Sampling System

In one embodiment, the six-primary color system uses a 4:2:0 sampling system. The 4:2:0 format is widely used in H.262/MPEG-2, H.264/MPEG-4 Part 10 and VC-1 compression. The process defined in SMPTE RP2050-1 provides a direct method to convert from a 4:2:2 sample structure to a 4:2:0 structure. When a 4:2:0 video decoder and encoder are connected via a 4:2:2 serial interface, the 4:2:0 data is decoded and converted to 4:2:2 by up-sampling the color difference component. In the 4:2:0 video encoder, the 4:2:2 video data is converted to 4:2:0 video data by down-sampling the color difference component.

There typically exists a color difference mismatch between the 4:2:0 video data from the 4:2:0 video data to be encoded. Several stages of codec concatenation are common through the processing chain. As a result, color difference signal mismatch between 4:2:0 video data input to 4:2:0 video encoder and 4:2:0 video output from 4:2:0 video decoder is accumulated and the degradation becomes visible.

Filtering within a Six-Primary Color System Using a 4:2:0 Sampling Method

When a 4:2:0 video decoder and encoder are connected via a serial interface, 4:2:0 data is decoded and the data is converted to 4:2:2 by up-sampling the color difference component, and then the 4:2:2 video data is mapped onto a serial interface. In the 4:2:0 video encoder, the 4:2:2 video data from the serial interface is converted to 4:2:0 video data by down-sampling the color difference component. At least one set of filter coefficients exists for 4:2:0/4:2:2 up-sampling and 4:2:2/4:2:0 down-sampling. The at least one set of filter coefficients provide minimally degraded 4:2:0 color difference signals in concatenated operations.

Filter Coefficients in a Six-Primary Color System Using a 4:2:0 Sampling Method

FIG. 42 illustrates one embodiment of a raster encoding diagram of sample placements for a six-primary color 4:2:0 progressive scan system. Within this compression process, horizontal lines show the raster on a display matrix. Vertical lines depict drive columns. The intersection of these is a pixel calculation. Data around a particular pixel is used to calculate color and brightness of the subpixels. Each “X” shows placement timing of the E_(Y) ₆ _(-INT) sample. Red dots depict placement of the E′_(CR-INT)+E′_(CC-INT) sample. Blue triangles show placement of the E′_(CB-INT)+E′_(CY-INT) sample.

In one embodiment, the raster is an RGB raster. In another embodiment, the raster is a RGBCYM raster.

System 3

FIG. 95 illustrates one embodiment of a system encode and decode process using a dual link method (“System 3”). System 3 utilizes a dual link method where two wires are used. RGB is sent to link A and CYM is sent to link B. After arriving at the image destination, the two links are recombined.

System 3 is simpler and more straight forward than Systems 1 and 2. The advantage with this system is that adoption is simply to format CYM on a second link. So, for an SDI design, RGB is sent on a standard SDI stream just as it is currently done. There is no modification to the transport and this link is operable to be sent to any RGB display requiring only the compensation for the luminance difference because the CYM components are not included. CYM data is transported in the same manner as RGB data. This data is then combined in the display to make up a 6P image. The downside is that the system requires two wires to move one image. This system is operable to work with most any format including SMPTE ST292, 424, 2082, and 2110. It also is operable to work with dual HDMI/CTA connections. In one embodiment, the system includes at least one transfer function (e.g., OETF, EOTF).

FIG. 96 illustrates one embodiment of an encoding process using a dual link method.

FIG. 97 illustrates one embodiment of a decoding process using a dual link method.

Comparison of Three Systems

Advantageously, System 1 fits within legacy SDI, CTA, and Ethernet transports. Additionally, System 1 has zero latency processing for conversion to an RGB display. However, System 1 is limited to 11-bit words.

System 2 is advantageously operable to transport 6 channels using 16-bit words with no compression. Additionally, System 2 fits within newer SDI, CTA, and Ethernet transport formats. However, System 2 requires double bit rate speed. For example, a 4K image requires a data rate for an 8K RGB image.

In comparison, System 3 is operable to transport 6 channels using 16-bit words with compression and at the same data rate required for a specific resolution. For example, a data rate for an RGB image is the same as for a 6P image using System 3. However, System 3 requires a twin cable connection within the video system.

Six-Primary Color System Backwards Compatibility

By designing the color gamut within the saturation levels of standard formats and using inverse color primary positions, it is easy to resolve an RGB image with minimal processing. In one embodiment for six-primary encoding, image data is split across three color channels in a transport system. In one embodiment, the image data is read as six-primary data. In another embodiment, the image data is read as RGB data. By maintaining a standard white point, the axis of modulation for each channel is considered as values describing two colors (e.g., blue and yellow) for a six-primary system or as a single color (e.g., blue) for an RGB system. This is based on where black is referenced. In one embodiment of a six-primary color system, black is decoded at a mid-level value. In an RGB system, the same data stream is used, but black is referenced at bit zero, not a mid-level.

In one embodiment, the RGB values encoded in the 6P stream are based on ITU-R BT.709. In another embodiment, the RGB values encoded are based on SMPTE RP431. Advantageously, these two embodiments require almost no processing to recover values for legacy display.

Two decoding methods are proposed. The first is a preferred method that uses very limited processing, negating any issues with latency. The second is a more straightforward method using a set of matrices at the end of the signal path to conform the 6P image to RGB.

In one embodiment, the decoding is for a 4:4:4 system. In one embodiment, the assumption of black places the correct data with each channel. If the 6P decoder is in the signal path, 11-bit values for RGB are arranged above bit value 2048, while CYM values are arranged below bit level 2047 as 11-bit. However, if this same data set is sent to a display or process that does not understand 6P processing, then that image data is assumed as black at bit value 0 as a full 12-bit word.

FIG. 43 illustrates one embodiment of the six-primary color unstack process in a 4:2:2 video system. Decoding starts by tapping image data prior to the unstacking process. The input to the 6P unstack will map as shown in FIG. 44. The output of the 6P decoder will map as shown in FIG. 45. This same data is sent uncorrected as the legacy RGB image data. The interpretation of the RGB decode will map as shown in FIG. 46.

Alternatively, the decoding is for a 4:2:2 system. This decode uses the same principles as the 4:4:4 decoder, but because a luminance channel is used instead of discrete color channels, the processing is modified. Legacy image data is still taken prior to unstack from the E′_(CB-INT)+E′_(CY-INT) and E′_(CR-INT)+E′_(CC-INT) channels as shown in FIG. 49.

FIG. 50 illustrates one embodiment of a non-constant luminance decoder with a legacy process. The dotted box marked (1) shows the process where a new component called E′_(-Y) is used to subtract the luminance levels that are present from the CYM channels from the E′_(CB-INT)+E′_(CY-INT) and E′_(CR-INT)+E′_(CC-INT) components as shown in box (2). The resulting output is now the R and B image components of the EOTF process. E′_(-Y) is also sent to the G matrix to convert the luminance and color difference components to a green output as shown in box (3). Thus, R′G′B′ is input to the EOTF process and output as G_(RGB), R_(RGB), and B_(RGB). In another embodiment, the decoder is a legacy RGB decoder for non-constant luminance systems.

For a constant luminance system, the process is very similar with the exception that green is calculated as linear as shown in FIG. 51.

Six-Primary Color System Using a Matrix Output

In one embodiment, the six-primary color system outputs a legacy RGB image. This requires a matrix output to be built at the very end of the signal path. FIG. 52 illustrates one embodiment of a legacy RGB image output at the end of the signal path. The design logic of the C, M, and Y primaries is in that they are substantially equal in saturation and placed at substantially inverted hue angles compared to R, G, and B primaries, respectively. In one embodiment, substantially equal in saturation refers to a ±10% difference in saturation values for the C, M, and Y primaries in comparison to saturation values for the R, G, and B primaries, respectively. In addition, substantially equal in saturation covers additional percentage differences in saturation values falling within the ±10% difference range. For example, substantially equal in saturation further covers a ±7.5% difference in saturation values for the C, M, and Y primaries in comparison to the saturation values for the R, G, and B primaries, respectively; a ±5% difference in saturation values for the C, M, and Y primaries in comparison to the saturation values for the R, G, and B primaries, respectively; a ±2% difference in saturation values for the C, M, and Y primaries in comparison to the saturation values for the R, G, and B primaries, respectively; a ±1% difference in saturation values for the C, M, and Y primaries in comparison to the saturation values for the R, G, and B primaries, respectively; and/or a ±0.5% difference in saturation values for the C, M, and Y primaries in comparison to the saturation values for the R, G, and B primaries, respectively. In a preferred embodiment, the C, M, and Y primaries are equal in saturation to the R, G, and B primaries, respectively. For example, the cyan primary is equal in saturation to the red primary, the magenta primary is equal in saturation to the green primary, and the yellow primary is equal in saturation to the blue primary.

In an alternative embodiment, the saturation values of the C, M, and Y primaries are not required to be substantially equal to their corollary primary saturation value among the R, G, and B primaries, but are substantially equal in saturation to a primary other than their corollary R, G, or B primary value. For example, the C primary saturation value is not required to be substantially equal in saturation to the R primary saturation value, but rather is substantially equal in saturation to the G primary saturation value and/or the B primary saturation value. In one embodiment, two different color saturations are used, wherein the two different color saturations are based on standardized gamuts already in use.

In one embodiment, substantially inverted hue angles refers to a ±10% angle range from an inverted hue angle (e.g., 180 degrees). In addition, substantially inverted hue angles cover additional percentage differences within the ±10% angle range from an inverted hue angle. For example, substantially inverted hue angles further covers a ±7.5% angle range from an inverted hue angle, a ±5% angle range from an inverted hue angle, a ±2% angle range from an inverted hue angle, a ±1% angle range from an inverted hue angle, and/or a ±0.5% angle range from an inverted hue angle. In a preferred embodiment, the C, M, and Y primaries are placed at inverted hue angles (e.g., 180 degrees) compared to the R, G, and B primaries, respectively.

In one embodiment, the gamut is the ITU-R BT.709-6 gamut. In another embodiment, the gamut is the SMPTE RP431-2 gamut.

For simplicity, the 6P gamut based on ITU-R BT.709 saturation is referred to as “6P-B”. The gamut based on SMPTE RP431-2 is referred to as “6P-C”. Referring back to the discussion on white point, 6P-B specifies a white point as D65. 6P-C uses a white point of D60. TABLE 14 and TABLE 15 show a comparison between the 6P RGBCYM and related RGB color primary placements.

TABLE 14 6P-B ITU-R BT.709 u′ v′ u′ v′ White 0.1978 0.4683 0.1978 0.4683 Red 0.4507 0.5229 0.4507 0.5229 Green 0.1250 0.5625 0.1250 0.5625 Blue 0.1754 0.1579 0.1754 0.1579 Yellow 0.2040 0.5650 Cyan 0.1000 0.4460 Magenta 0.3300 0.2930

TABLE 15 6P-C SMPTE RP431-2 u′ v′ u′ v′ White 0.2010 0.4740 0.2010 0.4740 Red 0.4964 0.5256 0.4964 0.5256 Green 0.098 0.5777 0.098 0.5777 Blue 0.1754 0.1579 0.1754 0.1579 Yellow 0.2078 0.5683 Cyan 0.0960 0.4540 Magenta 0.3520 0.3200

The unstack process includes output as six, 11-bit color channels that are separated and delivered to a decoder. To convert an image from a six-primary color system to an RGB image, at least two matrices are used. One matrix is a 3×3 matrix converting a six-primary color system image to XYZ values. A second matrix is a 3×3 matrix for converting from XYZ to the proper RGB color space. In one embodiment, XYZ values represent additive color space values, where XYZ matrices represent additive color space matrices. Additive color space refers to the concept of describing a color by stating the amounts of primaries that, when combined, create light of that color.

When a six-primary display is connected to the six-primary output, each channel will drive each color. When this same output is sent to an RGB display, the CYM channels are ignored and only the RGB channels are displayed. An element of operation is that both systems drive from the black area. At this point in the decoder, all are coded as bit value 0 being black and bit value 2047 being peak color luminance. This process can also be reversed in a situation where an RGB source can feed a six-primary display. The six-primary display would then have no information for the CYM channels and would display the input in a standard RGB gamut. FIG. 47 illustrates one embodiment of six-primary color output using a non-constant luminance decoder. FIG. 48 illustrates one embodiment of a legacy RGB process within a six-primary color system.

The design of this matrix is a modification of the CIE process to convert RGB to XYZ. First, u ‘v’ values are converted back to CIE 1931 xyz values using the following formulas:

$x = \frac{9u^{\prime}}{\left( {{6u^{\prime}} - {16v^{\prime}} + 12} \right)}$ $y = \frac{4v^{\prime}}{\left( {{6u^{\prime}} - {16v^{\prime}} + 12} \right)}$ z = 1 − x − y

Next, RGBCYM values are mapped to a matrix. The mapping is dependent upon the gamut standard being used. In one embodiment, the gamut is ITU-R BT.709-6. The mapping for RGBCYM values for an ITU-R BT.709-6 (6P-B) gamut are:

$\ {\left\lbrack {\begin{pmatrix} \; & x & y & z \\ R & 0.640 & 0.330 & 0.030 \\ G & 0.300 & 0.600 & 0.100 \\ B & 0.150 & 0.060 & 0.790 \\ C & 0.439 & 0.540 & 0.021 \\ Y & 0.165 & 0.327 & 0.509 \\ M & 0.320 & 0.126 & 0.554 \end{pmatrix}\begin{pmatrix} \; & R & G & B & C & Y & M \\ x & {{0.6}40} & {{0.3}00} & {{0.1}50} & {{0.4}39} & {{0.1}65} & {{0.3}19} \\ y & {{0.3}30} & {{0.6}00} & {{0.0}60} & {{0.5}40} & {{0.3}27} & {{0.1}26} \\ z & {{0.0}30} & {{0.1}00} & {{0.7}90} & {{0.0}21} & {{0.5}09} & {{0.5}54} \end{pmatrix}} \right\rbrack = \begin{pmatrix} {{0.5}19} & {{0.3}93} & {{0.1}40} \\ {{0.3}93} & {{0.4}60} & {{0.1}60} \\ {{0.1}40} & {{0.1}60} & {{0.6}50} \end{pmatrix}}$

In one embodiment, the gamut is SMPTE RP431-2. The mapping for RGBCYM values for a SMPTE RP431-2 (6P-C) gamut are:

$\left\lbrack {\begin{pmatrix} \; & x & y & z \\ R & 0.680 & 0.320 & 0.000 \\ G & 0.264 & 0.691 & 0.045 \\ B & 0.150 & 0.060 & 0.790 \\ C & 0.450 & 0.547 & 0.026 \\ Y & 0.163 & 0.342 & 0.496 \\ M & 0.352 & 0.142 & 0.505 \end{pmatrix}\begin{pmatrix} \; & R & G & B & C & Y & M \\ x & {{0.6}80} & {{0.2}64} & {{0.1}50} & {{0.4}50} & {{0.1}63} & {{0.3}52} \\ y & {{0.3}20} & {{0.6}90} & {{0.0}60} & {{0.5}47} & {{0.3}42} & {{0.1}42} \\ z & {{0.0}00} & {{0.0}45} & {{0.7}90} & {{0.0}26} & {{0.4}96} & {{0.5}05} \end{pmatrix}} \right\rbrack = \begin{pmatrix} {{0.5}65} & {{0.4}00} & {{0.1}21} \\ {{0.4}00} & {{0.5}49} & {{0.1}17} \\ {{0.1}21} & {{0.1}17} & {{0.6}50} \end{pmatrix}$

Following mapping the RGBCYM values to a matrix, a white point conversion occurs:

$X = \frac{x}{y}$ Y = 1 Z = 1 − x − y

For a six-primary color system using an ITU-R BT.709-6 (6P-B) color gamut, the white point is D65:

$0.9504 = \frac{{0.3}127}{{0.3}290}$ 0.3584 = 1 − 0.3127 − 0.3290

For a six-primary color system using a SMPTE RP431-2 (6P-C) color gamut, the white point is D60:

$0.9541 = \frac{{0.3}218}{{0.3}372}$ 0.3410 = 1 − 0.3218 − 0.3372

Following the white point conversion, a calculation is required for RGB saturation values, SR, SG, and SB. The results from the second operation are inverted and multiplied with the white point XYZ values. In one embodiment, the color gamut used is an ITU-R BT.709-6 color gamut. The values calculate as:

$\begin{bmatrix} S_{R} \\ S_{G} \\ S_{B} \end{bmatrix}^{{ITU} - {R\mspace{14mu}{BT}{.709}} - 6} = \left\lbrack {\begin{pmatrix} {{5.4}45} & {{- {4.6}}44} & {{- {0.0}}253} \\ {{- {4.6}}44} & {{6.3}37} & {{- {0.5}}63} \\ {{- {0.0}}253} & {{- {0.5}}63} & {{1.6}82} \end{pmatrix}\begin{pmatrix} {{0.9}50} \\ 1 \\ {{0.3}58} \end{pmatrix}} \right\rbrack$ Where

$\begin{bmatrix} S_{R} \\ S_{G} \\ S_{B} \end{bmatrix}^{{ITU} - {R\mspace{14mu}{BT}{.709}} - 6} = \begin{bmatrix} {{0.5}22} \\ {{1.7}22} \\ {{0.0}15} \end{bmatrix}$

In one embodiment, the color gamut is a SMPTE RP431-2 color gamut. The values calculate as:

$\begin{bmatrix} S_{R} \\ S_{G} \\ S_{B} \end{bmatrix}^{{{SMPTE}\mspace{14mu}{RP}\; 431} - 2} = \left\lbrack {\begin{pmatrix} {{3.6}92} & {{- {2.6}}49} & {{- {0.2}}11} \\ {{- {2.6}}49} & {{3.7}95} & {{- {0.1}}89} \\ {{- {0.2}}11} & {{- {0.1}}89} & {{1.6}11} \end{pmatrix}\begin{pmatrix} {{0.9}54} \\ 1 \\ {{0.3}41} \end{pmatrix}} \right\rbrack$ Where

$\begin{bmatrix} S_{R} \\ S_{G} \\ S_{B} \end{bmatrix}^{{{SMPTE}\mspace{20mu}{RP}\; 431} - 2} = \begin{bmatrix} {{0.8}02} \\ {{1.2}03} \\ {{0.1}59} \end{bmatrix}$

Next, a six-primary color-to-XYZ matrix must be calculated. For an embodiment where the color gamut is an ITU-R BT.709-6 color gamut, the calculation is as follows:

$\begin{bmatrix} X \\ Y \\ Z \end{bmatrix} = \left\lbrack \ {\begin{pmatrix} {{0.5}19} & {{0.3}93} & {{0.1}40} \\ {{0.3}93} & {{0.4}60} & {{0.1}60} \\ {{0.1}40} & {{0.1}60} & {{0.6}50} \end{pmatrix}^{{{ITU} - {R\mspace{14mu}{BT}{.709}} - 6}\ }\begin{pmatrix} {{0.5}22} & {{1.7}22} & {{0.1}53} \\ {{0.5}22} & {{1.7}22} & {{0.1}53} \\ {{0.5}22} & {{1.7}22} & {{0.1}53} \end{pmatrix}^{D\; 65}} \right\rbrack$ Wherein the resulting matrix is multiplied by the S_(R)S_(G)S_(B) matrix:

$\begin{bmatrix} X \\ Y \\ Z \end{bmatrix} = {\begin{bmatrix} {{0.2}71} & {{0.6}77} & {{0.0}02} \\ {{0.2}05} & {{0.7}92} & {{0.0}03} \\ {{0.0}73} & {{0.2}76} & {{0.0}10} \end{bmatrix}\begin{bmatrix} R \\ G \\ B \\ C \\ Y \\ M \end{bmatrix}}^{{ITU} - {R\mspace{14mu}{BT}{.709}} - 6}$ For an embodiment where the color gamut is a SMPTE RP431-2 color gamut, the calculation is as follows:

$\begin{bmatrix} X \\ Y \\ Z \end{bmatrix} = \left\lbrack \ {\begin{pmatrix} {{0.5}65} & {{0.4}01} & {{0.1}21} \\ {{0.4}01} & {{0.5}49} & {{0.1}17} \\ {{0.1}21} & {{0.1}17} & {{0.6}50} \end{pmatrix}^{{{SMPTE}\mspace{14mu}{RP}\; 431} - 2}\ \begin{pmatrix} {{0.8}02} & {{1.2}03} & {{0.1}59} \\ {{0.8}02} & {{1.2}03} & {{0.1}59} \\ {{0.8}02} & {{1.2}03} & {{0.1}59} \end{pmatrix}^{D\; 60}} \right\rbrack$ Wherein the resulting matrix is multiplied by the S_(R)S_(G)S_(B) matrix:

$\begin{bmatrix} X \\ Y \\ Z \end{bmatrix} = {\begin{bmatrix} {{0.4}53} & {{0.4}82} & {{0.0}19} \\ {{0.3}21} & {{0.6}60} & {{0.0}19} \\ {{0.0}97} & {{0.1}41} & {{0.1}03} \end{bmatrix}\begin{bmatrix} R \\ G \\ B \\ C \\ Y \\ M \end{bmatrix}}^{{{SMPTE}\mspace{14mu}{RP}\; 431} - 2}$

Finally, the XYZ matrix must converted to the correct standard color space. In an embodiment where the color gamut used is an ITU-R BT709.6 color gamut, the matrices are as follows:

$\begin{bmatrix} R \\ G \\ B \end{bmatrix}^{{ITU} - {R\mspace{14mu}{{BT}709}{.6}}} = {\begin{bmatrix} {{3.2}41} & {{- {1.5}}37} & {{- {0.4}}99} \\ {{- {0.9}}69} & {{1.8}76} & {{0.0}42} \\ {{0.0}56} & {{- {0.2}}04} & {{1.0}57} \end{bmatrix}\begin{bmatrix} X \\ Y \\ Z \end{bmatrix}}$

In an embodiment where the color gamut used is a SMPTE RP431-2 color gamut, the matrices are as follows:

$\begin{bmatrix} R \\ G \\ B \end{bmatrix}^{{{SMPTE}\mspace{14mu}{{RP}431}} - 2} = {\begin{bmatrix} {{2.7}3} & {{- {1.0}}18} & {{- {0.4}}40} \\ {{- {0.7}}95} & {{1.6}90} & {{0.0}23} \\ {{0.0}41} & {{- {0.0}}88} & {{1.1}01} \end{bmatrix}\begin{bmatrix} X \\ Y \\ Z \end{bmatrix}}$

Packing a Six-Primary Color System into IC_(T)C_(P)

IC_(T)C_(P) (ITP) is a color representation format specified in the Rec. ITU-R BT.2100 standard that is used as a part of the color image pipeline in video and digital photography systems for high dynamic range (HDR) and wide color gamut (WCG) imagery. The I (intensity) component is a luma component that represents the brightness of the video. C_(T) and C_(P) are blue-yellow (“tritanopia”) and red-green (“protanopia”) chroma components. The format is derived from an associated RGB color space by a coordination transformation that includes two matrix transformations and an intermediate non-linear transfer function, known as a gamma pre-correction. The transformation produces three signals: I, C_(T), and C_(P). The ITP transformation can be used with RGB signals derived from either the perceptual quantizer (PQ) or hybrid log-gamma (HLG) nonlinearity functions.

FIG. 53 illustrates one embodiment of packing six-primary color system image data into an IC_(T)C_(P) (ITP) format. In one embodiment, RGB image data is converted to an XYZ matrix. The XYZ matrix is then converted to an LMS matrix. The LMS matrix is then sent to an optical electronic transfer function (OETF). The conversion process is represented below:

$\begin{bmatrix} L \\ M \\ S \end{bmatrix} = {\left\lbrack {\begin{pmatrix} a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33} \end{pmatrix}\begin{pmatrix} {{0.3}59} & {{0.6}96} & {{- {0.0}}36} \\ {{- {0.1}}92} & {{1.1}00} & {{0.0}75} \\ {{0.0}07} & {{0.0}75} & {{0.8}43} \end{pmatrix}} \right\rbrack\begin{bmatrix} R \\ G \\ B \end{bmatrix}}$ Output from the OETF is converted to ITP format. The resulting matrix is:

$\left( {\begin{matrix} 0.5 \\ 1.614 \\ 4.378 \end{matrix}\begin{matrix} 0.5 \\ {- 3.323} \\ {- 4.246} \end{matrix}\begin{matrix} 0 \\ 1.710 \\ {- 0.135} \end{matrix}} \right)$

FIG. 54 illustrates one embodiment of a six-primary color system converting RGBCYM image data into XYZ image data for an ITP format (e.g., 6P-B, 6P-C). For a six-primary color system, this is modified by replacing the RGB to XYZ matrix with a process to convert RGBCYM to XYZ. This is the same method as described in the legacy RGB process. The new matrix is as follows for an ITU-R BT.709-6 (6P-B) color gamut:

$\begin{bmatrix} L \\ M \\ S \end{bmatrix} = {\begin{pmatrix} {{0.2}71} & {{0.6}77} & {{0.0}02} \\ {{0.2}05} & {{0.7}92} & {{0.0}03} \\ {{0.0}73} & {{0.2}77} & {{0.1}00} \end{pmatrix}{\begin{pmatrix} {{0.3}59} & {{0.6}96} & {{- {0.0}}36} \\ {{- {0.1}}92} & {{1.1}00} & {{0.0}75} \\ {{0.0}07} & {{0.0}75} & {{0.8}43} \end{pmatrix}\begin{bmatrix} R \\ G \\ B \\ C \\ Y \\ M \end{bmatrix}}^{{ITU} - {R\mspace{14mu}{BT}{.709}} - 6}}$

RGBCYM data, based on an ITU-R BT.709-6 color gamut, is converted to an XYZ matrix. The resulting XYZ matrix is converted to an LMS matrix, which is sent to an OETF. Once processed by the OETF, the LMS matrix is converted to an ITP matrix. The resulting ITP matrix is as follows:

$\left( {\begin{matrix} 0.5 \\ 1.614 \\ 4.378 \end{matrix}\begin{matrix} 0.5 \\ {- 3.323} \\ {- 4.246} \end{matrix}\begin{matrix} 0 \\ 1.710 \\ {- 0.135} \end{matrix}} \right)$

In another embodiment, the LMS matrix is sent to an Optical Optical Transfer Function (OOTF). In yet another embodiment, the LMS matrix is sent to a Transfer Function other than OOTF or OETF.

In another embodiment, the RGBCYM data is based on the SMPTE ST431-2 (6P-C) color gamut. The matrices for an embodiment using the SMPTE ST431-2 color gamut are as follows:

$\begin{bmatrix} L \\ M \\ S \end{bmatrix} = {\begin{pmatrix} {{0.4}53} & {{0.4}81} & {{0.0}19} \\ {{0.3}21} & {{0.6}60} & {{0.0}19} \\ {{0.0}97} & {{0.1}41} & {{0.1}03} \end{pmatrix}{\begin{pmatrix} {{0.3}59} & {{0.6}96} & {{- {0.0}}36} \\ {{- {0.1}}92} & {{1.1}00} & {{0.0}75} \\ {{0.0}07} & {{0.0}75} & {{0.8}43} \end{pmatrix}\begin{bmatrix} R \\ G \\ B \\ C \\ Y \\ M \end{bmatrix}}^{{{SMPTE}\mspace{14mu}{{ST}431}} - 2}}$ The resulting ITP matrix is:

$\left( {\begin{matrix} 0.5 \\ 1.614 \\ 4.378 \end{matrix}\begin{matrix} 0.5 \\ {- 3.323} \\ {- 4.246} \end{matrix}\begin{matrix} 0 \\ 1.710 \\ {- 0.135} \end{matrix}} \right)$

The decode process uses the standard ITP decode process, as the S_(R)S_(G)S_(B) cannot be easily inverted. This makes it difficult to recover the six RGBCYM components from the ITP encode. Therefore, the display is operable to use the standard ICtCp decode process as described in the standards and is limited to just RGB output.

Converting from Xyz to 6P Using Multiple Primary Triads

Another approach to converting an XYZ matrix, constructed using XYZ color data, to RGBCYM color data makes use of multiple primary triads. In one embodiment, primary triads are created using common edges within the color gamut. Primary triads include, but are not limited to, an RGB triad, a GCB triad, an RYG triad, and/or an RBM triad. By making use of primary triads, the system ensures that all areas of a color gamut are covered. The expected result is that at a boundary line for an alternate triad, results from RGB and the alternate triad are identical. However, this is not the case. While the results are not equal, values corresponding to the RGB triad and the alternate triad are in a specified ratio.

FIG. 100 illustrates one embodiment of a multi-primary triad color gamut using CIE-1931 color space.

This result is in part due to a non-equality between the main RGB triad and an adjacent triad, which indicates that the primary definitions were not using the same white point. By not using the same white point, an imbalance exists between the main RGB triad and the adjacent triad. To account for this imbalance, the six-primary color system data must be converted from device-independent coordinates. In one embodiment, the order of the primary triads is not important.

The conversion to the six-primary color system data from three-dimensional (3D) color space involves a degree of freedom, due in part to issues with metamerisms. In one embodiment, in order to convert between these formats efficiently, a number of matrices are created. These matrices perform “switch” operations, whereby matrices corresponding to six-primary color system data are swapped depending on the input chromaticity. In another embodiment, this process is performed using two-dimensional (2D) look-up tables. See, e.g., Takeshi Obi et al., Color Conversion Method for Multiprimary Display Using Matrix Switching, Optical Review Vol. 8, No. 3, May, 2001, at 191-197, which is incorporated herein by reference in its entirety.

In one embodiment, the matrices reflect REC 709 chromaticity coordinates in CIE 1931 color space. Table 16 illustrates RGB coordinates using a D65 white point in CIE 1931 color space.

TABLE 16 Primary X-coordinate Y-coordinate R 0.64 0.33 G 0.3 0.6 B 0.15 0.06 Wh (D65) 0.3127 0.329

In one embodiment, the matrices reflect REC 709 chromaticity coordinates in CIE 1976 color space. Table 17 illustrates RGB coordinates using a D65 white point in CIE 1976 color space.

TABLE 17 Primary u-coordinate v-coordinate X-coordinate Y-coordinate R 0.4507 0.5229 0.64000 0.3300 G 0.125 0.5625 0.3000 0.6000 B 0.1754 0.1579 0.15000 0.06000

In CIE-XYZ color space, a 3D color gamut, referred to as a color solid, by an additive mixture of multi-primaries becomes a polyhedron, where the color solid with the three base primaries, RGB, is represented by a hexahedron. When the spectral intensities of N primary lights are S_(j)(λ) [j=1, . . . , N], the total spectral intensity of the reconstructed light is given by:

${C(\lambda)} = {{\sum\limits_{j = 1}^{N}{\alpha_{j}{S_{j}(\lambda)}}} + {\beta(\lambda)}}$ where α_(j)(0≤α_(j)≤1) is the weight of the j-th primary color contributed by a modulating signal, and β(λ) is the spectral intensity of background light. In one embodiment, it is assumed S_(j)(λ) is the spectral intensity of each primary light full-emitted by a display device.

Using CIE-XYZ color matching functions x(λ), y(λ), and z(λ), the other CIE-XYZ color coordinates c=(c_(X), c_(Y), c_(Z))^(t) are reconstructed using an additive mixture of N primaries expressed as:

${c = {\begin{pmatrix} C_{x} \\ C_{y} \\ C_{z} \end{pmatrix} = {\sum\limits_{j = 1}^{N}{\alpha_{j}\begin{pmatrix} {\int\left\{ {{S_{j}(\lambda)} +} \right.} & {\left. {\beta(\lambda)} \right\}{\overset{¯}{x}(\lambda)}d\lambda} \\ {\int\left\{ {{S_{j}(\lambda)} +} \right.} & {\left. {\beta(\lambda)} \right\}{\overset{¯}{y}(\lambda)}d\lambda} \\ {\int\left\{ {{S_{j}(\lambda)} +} \right.} & {\left. {\beta(\lambda)} \right\}{\overset{¯}{z}(\lambda)}d\lambda} \end{pmatrix}}}}} = {{\sum\limits_{j = 1}^{N}{\alpha_{j}P_{j}}} + {b\mspace{20mu}\left( {0 \leq \alpha_{j} \leq 1} \right)}}$ where b=(b_(X), b_(Y), b_(Z))^(t) are the color coordinates of the background light and P_(j)=(P_(X) ^(j), P_(Y) ^(j), P_(Z) ^(j))^(t) is the color vector of the j-th primary color disregarding the background light.

The region c represented by the above equation corresponds to the gamut in CIE-XYZ color space. Applying the adequate weight, α_(j), to each primary color, the arbitrary color inside the primary color solid is reproduced. In one embodiment, the above equation assumes that each primary light has a constant chromaticity and is added to other primaries independently.

Table 18 illustrates chromaticity matrix values for a 6P-B system.

TABLE 18 u- v- X- Y- Primary coordinate coordinate coordinate coordinate Saturation R 0.4507 0.5229 0.64002 0.33002 3.4558 G 0.125 0.5625 0.30000 0.60000 2.0664 B 0.1754 0.1579 0.14997 0.06000 6.0598 C 0.1 0.446  0.16471 0.32650 1.3437 Y 0.204 0.565  0.43881 0.54015 1.8874 M 0.33 0.293  0.31963 0.12613 3.8261 Wh 0.1978 0.4683 0.3127  0.3290  N/A (D65)

Table 19 illustrates chromaticity matrix values for a 6P-C system. Note that the 6P-C system uses a white point of D60.

TABLE 19 Primary u v X Y Z R 0.4964 0.5256 0.68012 0.32006 −0.00018 G 0.098 0.5777 0.26369 0.69086  0.04544 B 0.1754 0.1579 0.14997 0.06000  0.79002 C 0.96 0.454 0.16265 0.34187  0.49548 Y 0.2078 0.5683 0.45022 0.54723  0.00255 M 0.352 0.32 0.35321 0.14235  0.50534 Wh (D60) 0.201 0.474 0.32177 0.33725  0.34098

Next, the signal from each primary color must be computed from the tristimulus values of CIE-XYZ. The signal for a multi-primary display is treated as α_(j)[j=1, . . . N]. In addition, the modulating signal applied to a display device is compensated from α_(j) depending on individual device characteristics. Device characteristics include, but are not limited to, gamma characteristics, luminance, luminance unity, visual acuity, flicker threshold, contrast, contrast polarity, resolution, refresh rate, temporal instability, persistence, color, and/or reflect characteristics. This conversion process is performed by inverting the following equation:

${\sum\limits_{j = 1}^{N}{\alpha_{j}P_{j}}} + {b\mspace{14mu}\left( {0 \leq \alpha_{j} \leq 1} \right)}$ as α=(α₁ , . . . ,N)^(t) =P ⁻(c−b) where P⁻ is a generalized inverse of the P=[P₁, . . . , N] and P is a 3×N matrix. Thus, the inversion includes a degree of freedom. In one embodiment, the dynamic range corresponding to a display device is under the constraint of 0≤α_(j)≤1. Therefore, the inverse equation requires only a partial nonlinear calculation. When color signals are converted to matrices, some values return as negative. These negative values are set to zero and then all matrices are combined.

Still, this conversion requires matrices for linear transforms, where the number of matrices is equal to the number of elements present. Here, the matrices are switched depending on the element where a specified color is included. In one embodiment, the matrix switching is performed using 2D look-up tables, reducing the system's overall computational requirements.

In one embodiment, a color solid is divided into a specified number of quadrangle pyramids. In another embodiment, a color solid for a multi-primary display is represented by a convex polyhedron fenced by parallelogram planes, where each parallelogram is covered by N-primary color vectors, starting from the coordinates of the sum of the other primary color vectors. As each parallelogram plane is constructed with a combination of two primary color vectors, the number of surface planes is equal to twice the number of combinations of primary vectors. This is expressed as: 2_(N) C _(N) =N(N−1)

Next, the color solid is divided into quadrangle pyramids, where the quadrangle pyramid basses are present at each surface plane except those pyramids with a vertex value at b, where b is a background light for each vertex of the color solid. As there are N surface planes containing b as a coordinate point, the total number of quadrangle pyramids is equal to N(N−1)−N=N(N−2) where the summit of each of the quadrangle pyramids is represented by the coordinates of b. The coordinates for the vertices at the base of each quadrangle pyramid are represented as q _(i)[i=1, . . . ,4] and the color coordinates, c, inside each of the quadrangle pyramids are expressed as c=ν[(q ₁ −b)+β(q ₂ −q ₁)+γ(q ₃ −q ₁)]+b where 0≤ν≤1, 0≤β≤1, and 0≤γ≤1. Vertices q₂ and q₃ are adjacent to q₁.

During the matrix switching process, additivity applies regardless of the number of primaries present. The complication this introduces is that by having more than three primaries, there are a variety of multi-primary signals corresponding to each visible color. Thus, the system needs to determine a single set of primary signals for each visible color. In one embodiment, the signals are chosen based on a lower inter-observer color variation. This results in smoother signals, as the system uses as many of the primary colors as possible in order to produce the right color and/or primary signal. In one embodiment, the signals are chosen based on how smooth the colors transition from one primary to the next. In another embodiment, the signals are chosen based on the ability of the system to minimize contouring. This avoids issues with contour jumping between adjacent primary colors and/or signals. In another embodiment, the signals are chosen based on mapping out-of-gamut colors to in-gamut colors. In yet another embodiment, the signals are chosen using multidimensional look-up tables, avoiding issues associated with interpolation. In yet another embodiment, the signals are chosen based on any combination of the aforementioned techniques. Signal capture methods and techniques are referred to as multi-spectral capture.

In a preferred embodiment, multi-channel signals from color imagery are created using an algorithm. The algorithm takes advantage of any of the previously mentioned signal-choosing techniques. In one embodiment, the algorithm is a blending algorithm. Blending refers to the process of layering multiple images into one image. Blending processes include, but are not limited to, division, addition, subtraction, difference blending, Boolean arithmetic blending processes, hue processes, luminosity processes, and/or saturation processes. Division blend processes divide pixel values of one layer with another layer, primarily useful when images require brightening. Addition blend processes add the pixel values of one layer to another layer, producing an image with pixel color values equal to that of the original layers. Subtraction blend processes subtract the pixel values of one layer from another layer. Difference blend processes subtracts pixel values of a bottom lay from the pixel values of a top layer, where the resulting image(s) display with a smooth transition. Boolean arithmetic blend processes combine the binary expansion of the hexadecimal color at each pixel of two layers using Boolean logic gates, where the top layer's alpha controls interpolation between the lower layer's image and a resulting combined image. Hue blending processes preserve the luma and chroma of a bottom layer, while simultaneously adopting the hue of a top layer. Saturation blend processes preserve the luma and hue of a bottom layer, while simultaneously adopting the chroma of a top layer. Luminosity blend processes preserve the hue and chroma of a bottom layer, while simultaneously adopting the luma of a top layer.

In one embodiment, the system is operable to blend multiple six-primary images for display using a gradient blending algorithm. In one embodiment, the system is operable to blend multiple six-primary images for display using a multi-frame exposure fusion algorithm, such as the one described in Anmol Biswas et al., Spatially Variant Laplacian Pyramids for Multi-Frame Exposure Fusion, February 2020, which is hereby incorporated by reference in its entirety.

The matrix switching process results in updated matrices corresponding to each of the 6P systems. Table 20 illustrates the results of matrix switching for a 6P-B system and Table 21 illustrates the results of matrix switching for a 6P-C system.

TABLE 20 Primary X Y u′ v′ R 0.640 0.330 0.451 0.523 Y 0.439 0.540 0.204 0.565 G 0.300 0.600 0.125 0.563 C 0.165 0.327 0.100 0.446 B 0.150 0.060 0.175 0.158 M 0.320 0.126 0.330 0.293 R 0.640 0.330 0.451 0.523

TABLE 21 Primary X Y u′ v′ R 0.680 0.320 0.496 0.526 Y 0.450 0.547 0.208 0.568 G 0.264 0.691 0.098 0.578 C 0.163 0.342 0.096 0.454 B 0.150 0.060 0.175 0.158 M 0.352 0.142 0.352 0.320 R 0.680 0.320 0.496 0.526

Converting Aces to 6P and then Converting Back to Aces

The Academy Color Encoding System (ACES) was designed by the Academy of Motion Picture Arts and Sciences to be an industry standard for color. ACES covers the entire process of filmmaking, including, but not limited to, image capture, editing, visual effects (VFX), presentation, archiving, and future remastering. More specifically, ACES is a series of guidelines and specifications for every type of color management. ACES guidelines include, but are not limited to, encoding specifications, transform definitions and guidelines, metadata definitions, standard screen specifications, and/or specifications for archive-ready image data and metadata. Furthermore, the ACES color space includes everything visible to the human eye. This means that the ACES color space is free of restrictions and/or limitations.

In order to convert from an ACES system to 6P, and then from 6P back to ACES, the system uses a pseudo-inverse matrix. In one embodiment, the pseudo-inverse matrix is an asymmetric matrix. However, using traditional color space matrices in the process results in the system outputting a negative value. This negative value translates into a “negative” color, which does not exist. As such, a negative value indicates that the incorrect primaries were being used for a specified color. Therefore, the system performs these matrix operations using triads, as described in the conversion from XYZ color space to 6P color space.

Each triad incorporates a set of three of the existing six primary colors. Each of these triads represents a subdivision of color space into different regions. In one embodiment, the system includes a primary triad. In one embodiment, the primary triad is RGM (Red, Green, Magenta). In another embodiment, the primary triad is CYM (Cyan, Yellow, Magenta). In another embodiment, the system includes a primary triad, a secondary triad, a tertiary triad, and a quaternary triad, wherein the primary triad is RGM, the secondary triad is GCB (Green, Cyan, Blue), the tertiary triad is RYB (Red, Yellow, Blue), and the quaternary triad is RBM (Red, Blue, Magenta). In yet another embodiment, there is no primary triad. In yet another embodiment, there are more than four triads.

FIG. 101 illustrates a table of Blue to Red line edge values between RGB and RMB triads.

Similar to the XYZ-to-6P conversion, the conversion from ACES to 6P, and then from 6P to ACES uses calculations based on XYZ values for each of the primaries. In one embodiment, this conversion process is only valid with in-gamut colors. For out-of-gamut colors, the 6P system converts these colors to in-gamut colors based on what the specific out-of-gamut color is. This conversion process does not require the pre-selection of matrices, as all matrices are converted and results are combined. In addition, ACES-to-6P-to-ACES conversion process does not require matrix switching, unlike the XYZ-to-6P conversion process.

FIG. 102 illustrates a YWV plot of a 6P system and an ACES 0 system.

FIG. 103 illustrates a table corresponding to chromaticity matrix values for a 6P system. The chromaticity matrix values reflect values corresponding to primaries in a 6P-B system. In order to initiate the conversion process, the following matrix is used to convert to YWV color space, where YWV represents a luminance-linear color space:

$\left( {\begin{matrix} 0 \\ {- 0.54} \\ 1.823 \end{matrix}\begin{matrix} 1 \\ {- 0.187} \\ {- 1.478} \end{matrix}\begin{matrix} 0 \\ 0.643 \\ {- 0.234} \end{matrix}} \right)$

In addition, the ACES-to-6P-to-ACES conversion process is operable to use the chromaticity values present in Table 18 for a 6P-B system and the chromaticity values present in Table 19 for a 6P-C system.

FIG. 104 illustrates a gamut using 6P-B chromaticity values for an ACES-to-6P-to-ACES conversion process.

In one embodiment, the ACES-to-6P-to-ACES conversion process first converts an RGB value in ACES D60 to XYZ. To convert the RGB value in ACES D60 to XYZ for a 6P-B system, the following equation is used:

$\begin{bmatrix} X \\ Y \\ Z \end{bmatrix} = {\begin{bmatrix} {{0.9}3865266} & {{- {0.0}}0574000} & {{0.0}1751701} \\ {{0.3}3810177} & {{0.7}2722662} & {{- {0.0}}6532839} \\ {{0.0}0072102} & {{0.0}0081573} & {{1.0}8726381} \end{bmatrix}\begin{bmatrix} R \\ G \\ B \end{bmatrix}}$

The 6P-B primaries are listed in Table 22 below.

TABLE 22 RXYZ 0.4124 0.2126 0.0193001 GXYZ 0.3576 0.7152 0.1192 BXYZ 0.1805 0.0721998 0.9505 CXYZ 0.15749 0.313266 0.48142 MXYZ 0.34276 0.13472 0.586662 YXYZ 0.450206 0.552013 0.0209755

The ACES-to-6P-to-ACES conversion process further includes a set of matrices enabling the conversion from RGB to 6P, where the set of matrices includes, but is not limited to, an XYZ-to-RGB matrix, an XYZ-to-CMY matrix, an XYZ-to-RMB matrix, an XYZ-to-BCG matrix, and/or an XYZ-to-GYR matrix. These matrices represent the matrix conversions for each primary triad used in the conversion from RGB to 6P. To create the matrices from D65 XYZ to the different primary triads, an inverse of the transpose of the three 6P-B primaries are taken. In one embodiment, an XYZ-to-RGB matrix is created using the inverse of the result from transposing an RXYZ matrix, an GXYZ matrix, and a BXY matrix. For example, to obtain the RGB triad, an inverse is taken of the transpose of a matrix created using the first three rows of Table 22. Table 23 lists matrix coefficients when converting from D65 XYZ color space to RGB in a 6P-B system using this process.

TABLE 23 3.240625 −1.537208 −0.498629 −0.968931 1.875756 0.041518 0.055710 −0.204021 1.056996

In one embodiment, an XYZ-to-CMY matrix is created using the inverse of the result from transposing a CXYZ matrix, a MXYZ matrix, and a YXYZ matrix. Table 24 lists matrix coefficients when converting from D65 XYZ color space to CMY in a 6P-B system.

TABLE 24 −3.496203 2.798197 1.400100 2.822710 −2.324505 0.589173 1.295195 0.790883 −0.938342

In one embodiment, an XYZ-to-RMB matrix is created using the inverse of the result from transposing a RXYZ matrix, a MXYZ matrix, and a BXYZ matrix. Table 25 lists matrix coefficients when converting from D65 XYZ color space to RMB in a 6P-B system.

TABLE 25 −7.51569 19.286 −0.0377284 17.6005 −34.0728 −0.754168 −10.7107 20.6386 1.51833

In one embodiment, an XYZ-to-BCG matrix is created using the inverse of the result from transposing a BXYZ matrix, a CXYZ matrix, and a GXYZ matrix. Table 26 lists matrix coefficients when converting from D65 XYZ color space to BCG in a 6P-B system.

TABLE 26 7.01624 −3.50579 −0.0140081 −15.341 7.27709 2.36049 6.01125 −1.43533 −1.03251

In one embodiment, an XYZ-to-GYR matrix is created using the inverse of the result from transposing a GXYZ matrix, a YXYZ matrix, and a RXYZ matrix. Table 27 lists matrix coefficients when converting from D65 XYZ color space to GYR in a 6P-B system.

TABLE 27 −0.457517 0.00285821 9.74466 −0.852221 3.121 −16.1693 3.7519 −3.40959 9.20183

The XYZ value is multiplied by each of the XYZ-to-triad matrices in Tables 23-27. The result of each multiplication is filtered for negative values. If a resulting matrix includes one or more negative values, all three values in the resulting matrix are set to zero. This results in a set of triad value 3-vectors, wherein the set of triad value 3-vectors is converted into RGBCYM 6-vectors by placing values at their respective component positions in the RGBCYM 6-vectors and placing zero values at the three unused component positions. If any of the merged colors are present in two triads (e.g., RGB and RMB), the values are divided by two (2) and merged back into the matrices, resulting in a set of final 6P values. If the merged colors do not have two triads, this represents the set of final 6P values.

The set of final 6P values is converted back to D65 XYZ space using a 6P-to-XYZ matrix. The 6P-to-XYZ matrix for 6P-B is listed below in Table 28.

TABLE 28 0.4124 0.3576 0.1805 0.15749 0.34276 0.450206 0.2126 0.7152 0.0721998 0.313266 0.13472 0.552013 0.0193001 0.1192 0.9505 0.48142 0.586662 0.0209755

Once this conversion is complete, the XYZ values are converted to ACES AP-0 using an XYZ-to-ACES matrix. This matrix is the inverse of the ACES-to-XYZ matrix. The matrix to convert from XYZ-to-ACES is listed below in Table 29.

TABLE 29 1.06234 0.00840371 −0.0166106 −0.493934 1.37109 0.0903398 −0.000333913 −0.00103425 0.919683

A similar process is used to convert from ACES to 6P-C and back to ACES. To convert the RGB value in ACES D60 to XYZ for a 6P-C system using an ACES white point, the following equation is used:

$\begin{bmatrix} X \\ Y \\ Z \end{bmatrix} = {\begin{bmatrix} {{0.9}525523959} & 0 & {{0.0}000936786} \\ {{0.3}439664498} & {{0.7}281660966} & {{- {0.0}}721325464} \\ 0 & 0 & {{1.0}088251844} \end{bmatrix}\begin{bmatrix} R \\ G \\ B \end{bmatrix}}$

The 6P-C primaries are listed in Table 29 below.

TABLE 29 RXYZ 0.50495 0.237623 0 GXYZ 0.264681 0.689171 0.0449459 BXYZ 0.183015 0.073206 0.963879 CXYZ 0.159136 0.336795 0.473821 MXYZ 0.371236 0.149949 0.532566 YXYZ 0.422273 0.513256 0.00243872

In one embodiment, an XYZ-to-RGB matrix is created using the inverse of the result from transposing an RXYZ matrix, an GXYZ matrix, and a BXY matrix. For example, to obtain the RGB triad, an inverse is taken of the transpose of a matrix created using the first three rows of Table 29 for 6P-C. Table 30 lists matrix coefficients when converting from D65 XYZ color space to RGB in a 6P-C system using an ACES white point.

TABLE 30 2.383102 −0.884257 −0.385227 −0.833577 1.771364 0.023701 0.039354 −0.083038 1.034036

In one embodiment, an XYZ-to-CMY matrix is created using the inverse of the result from transposing a CXYZ matrix, a MXYZ matrix, and a YXYZ matrix. Table 31 lists matrix coefficients when converting from D65 XYZ color space to CMY in a 6P-C system using an ACES white point.

TABLE 31 −2.961772 2.430264 1.380316 2.680304 −2.208133 0.643688 1.116764 1.009092 −1.062840

In one embodiment, an XYZ-to-RMB matrix is created using the inverse of the result from transposing a RXYZ matrix, a MXYZ matrix, and a BXYZ matrix. Table 32 lists matrix coefficients when converting from D65 XYZ color space to RMB in a 6P-C system using an ACES white point.

TABLE 32 −12.258108 30.228550 0.031061 26.945451 −57.259520 −0.766129 −14.7577636 31.361077 1.454757

In one embodiment, an XYZ-to-BCG matrix is created using the inverse of the result from transposing a BXYZ matrix, a CXYZ matrix, and a GXYZ matrix. Table 33 lists matrix coefficients when converting from D65 XYZ color space to BCG in a 6P-C system using an ACES white point.

TABLE 33 11.109755 −4.190743 −0.755486 −23.321462 8.653499 3.769897 10.042078 −2.264081 −1.734341

In one embodiment, an XYZ-to-GYR matrix is created using the inverse of the result from transposing a GXYZ matrix, a YXYZ matrix, and a RXYZ matrix. Table 34 lists matrix coefficients when converting from D65 XYZ color space to GYR in a 6P-C system using an ACES white point.

TABLE 34 0.098523 −0.195369 24.514579 −1.650905 3.483415 −43.377476 3.305661 −2.830859 23.854979

The XYZ value is multiplied by each of the XYZ-to-triad matrices in Tables 30-34. The result of each multiplication is filtered for negative values. If a resulting matrix includes one or more negative values, all three values in the resulting matrix are set to zero. This results in a set of triad vectors. If any of the merged colors are present in two triads (e.g., RGB and RMB), the values are divided by two (2) and merged back into the matrices, resulting in a set of final 6P values. If the merged colors do not have two triads, this represents the set of final 6P values.

The set of final 6P values is converted back to XYZ space with an ACES white point using a 6P-to-XYZ matrix. The 6P-to-XYZ matrix for 6P-C is listed below in Table 35.

TABLE 35 0.50495 0.264681 0.183015 0.159136 0.371236 0.422273 0.237623 0.689171 0.073206 0.336795 0.149949 0.513256 0 0.0449459 0.963879 0.473821 0.532566 0.00243872

Once this conversion is complete, the XYZ values are converted to ACES AP-0 using an XYZ-to-ACES matrix. This matrix is the inverse of the ACES-to-XYZ matrix. The matrix to convert from XYZ-to-ACES is listed below in Table 36.

TABLE 36 1.0498110175 0 −0.0000974845 −0.4959030231 1.3733130458 0.0982400361 0 0 0.9912520182

In one embodiment, the conversion process from ACES-to-6P makes use of a matrix conversion from RGB color data to five separate primary triads: an RGB primary triad, a CMY primary triad, an RMB primary triad, a BCG primary triad, and a GYR primary triad. Once converted, the resulting triads are evaluated by the system, wherein the system is operable to identify instances where any value and/or component within a primary triad is less than zero. When the system encounters an instance where the value and/or component within a specific primary triad is less than zero, all of that specific primary triad's values are set to zero.

Next, the primary components of the triads are then added together on a per-component basis (e.g., {SUM(R), SUM(G), SUM(B), SUM(C), SUM(M), SUM(Y)}). For any ACES AP-0 value where color signal values for two primary triads are all non-negative, the sum of each primary component is divided by two. It is not possible for more than two primary triads to be completely non-negative. The result of this process is a set of output data in 6P color space (RGBCMY).

If all of the RGBCMY triad values are negative, this color is out-of-gamut for 6P and must be gamut mapped to an in-gamut color. In one embodiment, signals for the triad with the least-negative minimum value are used, with the negative signal values clipped to zero. These signal values are then used on a per-component basis for each out-of-gamut-signal.

FIG. 105 illustrates a process to validate the ACES-to-6P-to-ACES conversion process according to one embodiment of the present invention. First, a set of ISO chart values are defined in ACES for an ACES-to-XYZ matrix and XYZ-6P Primary Triads: XYZ-to-RGB, XYZ-to-CMY, XYZ-to-RMB, XYZ-to-BCG, and XYZ-to-GYR matrices. ISO chart values are then found using each of the previously mentioned triad matrices. Next, each triad matrix is filtered, where any negative values are set to zero. Once the triad matrices have been filtered, the triad values are merged, per primary component (RGBCMY). If any of the merged colors have two triads (e.g., RGB and CMY), the values are divided by two (2) and merged back into the matrices, resulting in a set of final 6P values. If the merged colors do not have two triads, this represents the set of final 6P values. Then, the set of final 6P values is converted back to XYZ space using a 6P-to-XYZ matrix. Once this conversion is complete, the XYZ values are converted to ACES AP-0 using an inverse ACES-to-XYZ matrix. Upon completing the conversion to ACES AP-0, the recovered ACES colors are subtracted from the original ACES ISO chart values. If this subtraction results in a value other than zero, the entire conversion process is restarted. Otherwise, if the result is equal to zero, this indicates that the conversion process is successful.

In one embodiment, the ISO 17321 matrix/chart values are defined using a perfect reflecting diffuser matrix (0.97784 0.97784 0.97784), an 18% grey card matrix (0.18 0.18 0.18), and the 24 patches of the ISO 17321-1 chart, as illuminated using CIE D60:

(0.11877 0.08709 0.05895), (0.40002 0.31916 0.23737),

(0.18476 0.20398 0.31311), (0.10901 0.13511 0.06493),

(0.26684 0.24604 0.40932), (0.32283 0.46208 0.40606),

(0.38606 0.22744 0.05777), (0.13822 0.13037 0.33703),

(0.30203 0.13752 0.12758), (0.0931 0.06347 0.13525),

(0.34876 0.43654 0.10614), (0.48656 0.36686 0.08061),

(0.08732 0.07443 0.27274), (0.15366 0.25691 0.09071),

(0.21742 0.0707 0.0513), (0.5892 0.53943 0.09157),

(0.30904 0.14818 0.27426), (0.14901 0.23378 0.35939),

(0.86653 0.86792 0.85818), (0.57356 0.57256 0.57169),

(0.35346 0.35337 0.35391), (0.20253 0.20243 0.20287),

(0.09467 0.0952 0.09637), (0.03745 0.03766 0.03895).

These are the ACES RICD values for a perfect reflecting diffuser, an 18% gray card, and the 24 patches of the ISO 17321-1 chart, as illuminated using CIE D60.

While the process shown in FIG. 105 is using the ACES RICD values for a perfect reflecting diffuser, an 18% gray card, and the 24 patches of the ISO 17321-1 chart, as illuminated using CIE D60, it can be used to validate any conversion from ACES-to-6P-to-ACES.

In one embodiment using ITU-R BT.2100 color space, it is necessary to perform a scaling operation of the linear display-referred RGB values, followed by applying an inverse Perceptual Quantizer (PQ) EOTF. The scaling is such that 6P data maps to 10-bit PQ. In one embodiment, the scaling maps at a rate of 403 candelas per square meter (cd/m²).

Converting to a Five-Color Multiprimary Display

In one embodiment, the system is operable to convert image data incorporating five primary colors. In one embodiment, the five primary colors include Red (R), Green (G), Blue (G), Cyan (C), and Yellow (Y), collectively referred to as RGBCY. In one embodiment, the five primary colors include Red (R), Green (G), Blue (B), Cyan (C), and Orange (O), collectively referred to as RGBCO. RGBCO primaries provide optimal spectral characteristics, transmittance characteristics, and makes use of a D65 white point. See, e.g., Moon-Cheol Kim et al., Wide Color Gamut Five Channel Multi-Primary for HDTV Application, Journal of Imaging Sci. & Tech. Vol. 49, No. 6, November/December 2005, at 594-604, which is hereby incorporated by reference in its entirety.

In one embodiment, a five-primary color model is expressed as F=M.C, where F is equal to a tristimulus color vector, F=(X, Y, Z)^(T), and Cis equal to a linear display control vector, C=(C1, C2, C3, C4, C5)^(T). Thus, a conversion matrix for the five-primary color model is represented as

$M = \begin{pmatrix} X_{1} & X_{2} & X_{3} & X_{4} & X_{5} \\ Y_{1} & Y_{2} & Y_{3} & Y_{4} & Y_{5} \\ Z_{1} & Z_{2} & Z_{3} & Z_{4} & Z_{5} \end{pmatrix}$

Using the above equation and matrix, a gamut volume is calculated for a set of given control vectors on the gamut boundary. The control vectors are converted into CIELAB uniform color space. However, because matrix M is non-square, the matrix inversion requires splitting the color gamut into a specified number of pyramids, with the base of each pyramid representing an outer surface and where the control vectors are calculated using linear equation for each given XYT triplet present within each pyramid. By separating regions into pyramids, the conversion process is normalized. In one embodiment, a decision tree is created in order to determine which set of primaries are best to define a specified color. In one embodiment, a specified color is defined by multiple sets of primaries. In order to locate each pyramid, 2D chromaticity look-up tables are used, with corresponding pyramid numbers for input chromaticity values in xy or u ‘v’. Typical methods using pyramids require 1000×1000 address ranges in order to properly search the boundaries of adjacent pyramids with look-up table memory. The system of the present invention uses a combination of parallel processing for adjacent pyramids and at least one algorithm for verifying solutions by checking constraint conditions. In one embodiment, the system uses a parallel computing algorithm. In one embodiment, the system uses a sequential algorithm. In another embodiment, the system uses a brightening image transformation algorithm. In another embodiment, the system uses a darkening image transformation algorithm. In another embodiment, the system uses an inverse sinusoidal contrast transformation algorithm. In another embodiment, the system uses a hyperbolic tangent contrast transformation algorithm. In yet another embodiment, the system uses a sine contrast transformation execution times algorithm. In yet another embodiment, the system uses a linear feature extraction algorithm. In yet another embodiment, the system uses a JPEG2000 encoding algorithm. In yet another embodiment, the system uses a parallelized arithmetic algorithm. In yet another embodiment, the system uses an algorithm other than those previously mentioned. In yet another embodiment, the system uses any combination of the aforementioned algorithms.

Mapping a Six-Primary Color System into Standardized Transport Formats

Each encode and/or decode system fits into existing video serial data streams that have already been established and standardized. This is key to industry acceptance. Encoder and/or decoder designs require little or no modification for a six-primary color system to map to these standard serial formats.

FIG. 55 illustrates one embodiment of a six-primary color system mapping to a SMPTE ST424 standard serial format. The SMPTE ST424/ST425 set of standards allow very high sampling systems to be passed through a single cable. This is done by using alternating data streams, each containing different components of the image. For use with a six-primary color system transport, image formats are limited to RGB due to the absence of a method to send a full bandwidth Y signal.

The process for mapping a six-primary color system to a SMPTE ST425 format is the same as mapping to a SMPTE ST424 format. To fit a six-primary color system into a SMPTE ST425/424 stream involves the following substitutions: G′_(INT)+M′_(INT) is placed in the Green data segments, R′_(INT)+C′_(INT) is placed in the Red data segments, and B′_(INT)+Y′_(INT) is placed into the Blue data segments. FIG. 56 illustrates one embodiment of an SMPTE 424 6P readout.

System 2 requires twice the data rate as System 1, so it is not compatible with SMPTE 424. However, it maps easily into SMPTE ST2082 using a similar mapping sequence. In one example, system 2 is used to have the same data speed defined for 8K imaging to show a 4K image.

FIG. 57 and FIG. 58 illustrate serial digital interfaces for a six-primary color system using the SMPTE ST2082 standard. In one embodiment, the six-primary color system data is RGBCYM data, which is mapped to the SMPTE ST2082 standard (FIG. 57). In one embodiment, the six-primary color system data is Y_(RGB) Y_(CYM) C_(R) C_(B) C_(C) C_(Y) data, which is mapped to the SMPTE ST2082 standard (FIG. 58).

In one embodiment, the standard serial format is SMPTE ST292. SMPTE ST292 is an older standard than ST424 and is a single wire format for 1.5 GB video, whereas ST424 is designed for up to 3 GB video. However, while ST292 can identify the payload ID of SMPTE ST352, it is constrained to only accepting an image identified by a hex value, 0h. All other values are ignored. Due to the bandwidth and identifications limitations in ST292, a component video six-primary color system incorporates a full bit level luminance component. To fit a six-primary color system into a SMPTE ST292 stream involves the following substitutions: E′_(Y) ₆ _(-INT) is placed in the Y data segments, E′_(Cb-INT)+E′_(Cy-INT) is placed in the Cb data segments, and E′_(Cr-INT)+E′_(Cc-INT) is placed in the Cr data segments. In another embodiment, the standard serial format is SMPTE ST352.

SMPTE ST292 and ST424 Serial Digital Interface (SDI) formats include payload identification (ID) metadata to help the receiving device identify the proper image parameters. The tables for this need modification by adding at least one flag identifying that the image source is a six-primary color RGB image. Therefore, six-primary color system format additions need to be added. In one embodiment, the standard is the SMPTE ST352 standard.

FIG. 59 illustrates one embodiment of an SMPTE ST292 6P mapping. FIG. 60 illustrates one embodiment of an SMPTE ST292 6P readout.

FIG. 61 illustrates modifications to the SMPTE ST352 standards for a six-primary color system. Hex code “Bh” identifies a constant luminance source and flag “Fh” indicates the presence of a six-primary color system. In one embodiment, Fh is used in combination with at least one other identifier located in byte 3. In another embodiment, the Fh flag is set to 0 if the image data is formatted as System 1 and the Fh flag is set to 1 if the image data is formatted as System 2.

In another embodiment, the standard serial format is SMPTE ST2082. Where a six-primary color system requires more data, it may not always be compatible with SMPTE ST424. However, it maps easily into SMPTE ST2082 using the same mapping sequence. This usage would have the same data speed defined for 8K imaging in order to display a 4K image.

In another embodiment, the standard serial format is SMPTE ST2022. Mapping to ST2022 is similar to mapping to ST292 and ST242, but as an ETHERNET format. The output of the stacker is mapped to the media payload based on Real-time Transport Protocol (RTP) 3550, established by the Internet Engineering Task Force (IETF). RTP provides end-to-end network transport functions suitable for applications transmitting real-time data, including, but not limited to, audio, video, and/or simulation data, over multicast or unicast network services. The data transport is augmented by a control protocol (RTCP) to allow monitoring of the data delivery in a manner scalable to large multicast networks, and to provide control and identification functionality.

FIG. 62 illustrates one embodiment of a modification for a six-primary color system using the SMPTE ST2202 standard. For SMPTE ST2202-6:2012 (HBRMT), there are no changes needed in formatting or mapping of the bit packing. ST2022 relies on header information to correctly configure the media payload. Parameters for this are established within the payload header using the video source format fields including, but not limited to, MAP, FRAME, FRATE, and/or SAMPLE. MAP, FRAME, and FRATE remain as described in the standard. MAP is used to identify if the input is ST292 or ST425 (RGB or Y Cb Cr). SAMPLE is operable for modification to identify that the image is formatted as a six-primary color system image. In one embodiment, the image data is sent using flag “0h” (unknown/unspecified).

In another embodiment, the standard is SMPTE ST2110. SMPTE ST2110 is a relatively new standard and defines moving video through an Internet system. The standard is based on development from the IETF and is described under RFC3550. Image data is described through “pgroup” construction. Each pgroup consists of an integer number of octets. In one embodiment, a sample definition is RGB or YCbCr and is described in metadata. In one embodiment, the metadata format uses a Session Description Protocol (SDP) format. Thus, pgroup construction is defined for 4:4:4, 4:2:2, and 4:2:0 sampling as 8-bit, 10-bit, 12-bit, and in some cases 16-bit and 16-bit floating point wording. In one embodiment, six-primary color image data is limited to a 10-bit depth. In another embodiment, six-primary color image data is limited to a 12-bit depth. Where more than one sample is used, it is described as a set. For example, 4:4:4 sampling for blue, as a non-linear RGB set, is described as C0′B, C1′B, C2′B, C3′B, and C4′B. The lowest number index being left most within the image. In another embodiment, the method of substitution is the same method used to map six-primary color content into the ST2110 standard.

In another embodiment, the standard is SMPTE ST2110. SMPTE ST2110-20 describes the construction for each pgroup. In one embodiment, six-primary color system content arrives for mapping as non-linear data for the SMPTE ST2110 standard. In another embodiment, six-primary color system content arrives for mapping as linear data for the SMPTE ST2110 standard.

FIG. 63 illustrates a table of 4:4:4 sampling for a six-primary color system for a 10-bit video system. For 4:4:4 10-bit video, 15 octets are used and cover 4 pixels.

FIG. 64 illustrates a table of 4:4:4 sampling for a six-primary color system for a 12-bit video system. For 4:4:4 12-bit video, 9 octets are used and cover 2 pixels before restarting the sequence.

Non-linear GRBMYC image data would arrive as: G′_(INT)+M′_(INT), R′_(INT)+C′_(INT), and B′_(INT)+Y′_(INT). Component substitution would follow what has been described for SMPTE ST424, where G′_(INT)+M′_(INT) is placed in the Green data segments, R′_(INT)+C′_(INT) is placed in the Red data segments, and B′_(INT)+Y′_(INT) is placed in the Blue data segments. The sequence described in the standard is shown as R0′, G0′, B0′, R1′, G1′, B1′, etc.

FIG. 65 illustrates sequence substitutions for 10-bit and 12-bit video in 4:2:2 sampling systems in a Y Cb Cr Cc Cy color space. Components are delivered to a 4:2:2 pgroup including, but not limited to, E′_(Y) ₆ _(-INT), E′_(Cb-INT)+E′_(Cy-INT), and E′_(Cr-INT)+E′_(Cc-INT). For 4:2:2 10-bit video, 5 octets are used and cover 2 pixels. For 4:2:2 12-bit video, 6 octets are used and cover 2 pixels before restarting the sequence. Component substitution follows what has been described for SMPTE ST292, where E′_(Y) ₆ _(-INT) is placed in the Y data segments, E′_(Cb-INT)+E′_(Cy-INT) is placed in the Cb data segments, and E′_(Cr-INT)+E′_(Cc-INT) is placed in the Cr data segments. The sequence described in the standard is shown as Cb0′, Y0′, Cr0′, Y1′, Cr1′, Y3′, Cb2′, Y4′, Cr2′, Y5′, etc. In another embodiment, the video data is represented at a bit level other than 10-bit or 12-bit. In another embodiment, the sampling system is a sampling system other than 4:2:2. In another embodiment, the standard is STMPE ST2110.

FIG. 66 illustrates sample placements of six-primary system components for a 4:2:2 sampling system image. This follows the substitutions illustrated in FIG. 65, using a 4:2:2 sampling system.

FIG. 67 illustrates sequence substitutions for 10-bit and 12-bit video in 4:2:0 sampling systems using a Y Cb Cr Cc Cy color space. Components are delivered to a pgroup including, but not limited to, E′_(Y6-INT), E′_(Cb-INT)+E′_(Cy-INT), and E′_(Cr-INT)+E′_(Cc-INT). For 4:2:0 10-bit video data, 15 octets are used and cover 8 pixels. For 4:2:0 12-bit video data, 9 octets are used and cover 4 pixels before restarting the sequence. Component substitution follows what is described in SMPTE ST292 where E′_(Y6-INT)+E′_(Cc-INT) is placed in the Y data segments, E′_(Cb-INT)+E′_(Cy-INT) is placed in the Cb data segments, and E′_(Cr-INT)+E′_(Cc-INT) is placed in the Cr data segments. The sequence described in the standard is shown as Y′00, Y′01, Y′, etc.

FIG. 68 illustrates sample placements of six-primary system components for a 4:2:0 sampling system image. This follows the substitutions illustrated in FIG. 67, using a 4:2:0 sampling system.

FIG. 69 illustrates modifications to SMPTE ST2110-20 for a 10-bit six-primary color system in 4:4:4 video. SMPTE ST2110-20 describes the construction of each “pgroup”. Normally, six-primary color system data and/or content would arrive for mapping as non-linear. However, with the present system there is no restriction on mapping data and/or content. For 4:4:4, 10-bit video, 15 octets are used and cover 4 pixels before restarting the sequence. Non-linear, six-primary color system image data would arrive as G′_(INT), B′_(INT), R′_(INT), M′_(INT), Y′_(INT), and C′_(INT). The sequence described in the standard is shown as R0′, G0′, B0′, R1′, G1′, B1′, etc.

FIG. 70 illustrates modifications to SMPTE ST2110-20 for a 12-bit six-primary color system in 4:4:4 video. For 4:4:4, 12-bit video, 9 octets are used and cover 2 pixels before restarting the sequence. Non-linear, six-primary color system image data would arrive as G′_(INT), B′_(INT), R′_(INT), M′_(INT), Y′_(INT), and C′_(INT). The sequence described in the standard is shown as R0′, G0′, B0′, R1′, G1′, B1′, etc.

FIG. 71 illustrates modifications to SMPTE ST2110-20 for a 10-bit six primary color system in 4:2:2 video. Components that are delivered to a SMPTE ST2110 pgroup include, but are not limited to, E′_(Yrgb-INT), E′_(Ycym-INT), E′_(Cb-INT), E′_(Cr-INT), E′_(Cy-INT), and E′_(Cc-INT). For 4:2:2, 10-bit video, 5 octets are used and cover 2 pixels before restarting the sequence. For 4:2:2:2, 12-bit video, 6 octets are used and cover 2 pixels before restarting the sequence. Component substitution follows what is described for SMPTE ST292, where E′_(Yrgb-INT) or E′_(Ycym-INT) are placed in the Y data segments, E′_(Cr-INT) or E′_(Cc-INT) are placed in the Cr data segments, and E′_(Cb-INT) or E′_(Cy-INT) are placed in the Cb data segments. The sequence described in the standard is shown as Cb′0, Y′0, Cr′0, Y′1, Cb′1, Y′2, Cr′1, Y′3, Cb′2, Y′4, Cr′2, etc.

FIG. 72 illustrates modifications to SMPTE ST2110-20 for a 12-bit six-primary color system in 4:2:0 video. Components that are delivered to a SMPTE ST2110 pgroup are the same as with the 4:2:2 method. For 4:2:0, 10-bit video, 15 octets are used and cover 8 pixels before restarting the sequence. For 4:2:0, 12-bit video, 9 octets are used and cover 4 pixels before restarting the sequence. Component substitution follows what is described for SMPTE ST292, where E′_(Yrgb-INT) or E′_(Ycym-INT) are placed in the Y data segments, E′_(Cr-INT) or E′_(Cc-INT) are placed in the Cr data segments, and E′_(Cb-INT) or E′_(Cy-INT) are placed in the Cb data segments. The sequence described in the standard is shown as Y′00, Y′01, Y′, etc.

Session Description Protocol (SDP) Modification for a Six-Primary Color System

SDP is derived from IETF RFC 4566 which sets parameters including, but not limited to, bit depth and sampling parameters. In one embodiment, SDP parameters are contained within the RTP payload. In another embodiment, SDP parameters are contained within the media format and transport protocol. This payload information is transmitted as text. Therefore, modifications for the additional sampling identifiers requires the addition of new parameters for the sampling statement. SDP parameters include, but are not limited to, color channel data, image data, framerate data, a sampling standard, a flag indicator, an active picture size code, a timestamp, a clock frequency, a frame count, a scrambling indicator, and/or a video format indicator. For non-constant luminance imaging, the additional parameters include, but are not limited to, RGBCYM-4:4:4, YBRCY-4:2:2, and YBRCY-4:2:0. For constant luminance signals, the additional parameters include, but are not limited to, CLYBRCY-4:2:2 and CLYBRCY-4:2:0.

Additionally, differentiation is included with the colorimetry identifier in one embodiment. For example, 6PB1 defines 6P with a color gamut limited to ITU-R BT.709 formatted as system 1, 6PB2 defines 6P with a color gamut limited to ITU-R BT.709 formatted as system 2, 6PB3 defines 6P with a color gamut limited to ITU-R BT.709 formatted as system 3, 6PC1 defines 6P with a color gamut limited to SMPTE RP 431-2 formatted as system 1, 6PC2 defines 6P with a color gamut limited to SMPTE RP 431-2 formatted as system 2, 6PC3 defines 6P with a color gamut limited to SMPTE RP 431-2 formatted as system 3, 6PS1 defines 6P with a color gamut as Super 6P formatted as system 1, 6PS2 defines 6P with a color gamut as Super 6P formatted as system 2, and 6PS3 defines 6P with a color gamut as Super 6P formatted as system 3.

Colorimetry can also be defined between a six-primary color system using the ITU-R BT.709-6 standard and the SMPTE ST431-2 standard, or colorimetry can be left defined as is standard for the desired standard. For example, the SDP parameters for a 1920×1080 six-primary color system using the ITU-R BT.709-6 standard with a 10-bit signal as system 1 are as follows: m=video 30000 RTP/AVP 112, a=rtpmap: 112 raw/90000, a=fmtp: 112, sampling=YBRCY-4:2:2, width=1920, height=1080, exactframerate=30000/1001, depth=10, TCS=SDR, colorimetry=6PB1, PM=2110GPM, SSN=ST2110-20:2017.

In one embodiment, the six-primary color system is integrated with a Consumer Technology Association (CTA) 861-based system. CTA-861 establishes protocols, requirements, and recommendations for the utilization of uncompressed digital interfaces by consumer electronics devices including, but not limited to, digital televisions (DTVs), digital cable, satellite or terrestrial set-top boxes (STBs), and related peripheral devices including, but not limited to, DVD players and/or recorders, and other related Sources or Sinks.

These systems are provided as parallel systems so that video content is parsed across several line pairs. This enables each video component to have its own transition-minimized differential signaling (TMDS) path. TMDS is a technology for transmitting high-speed serial data and is used by the Digital Visual Interface (DVI) and High-Definition Multimedia Interface (HDMI) video interfaces, as well as other digital communication interfaces. TMDS is similar to low-voltage differential signaling (LVDS) in that it uses differential signaling to reduce electromagnetic interference (EMI), enabling faster signal transfers with increased accuracy. In addition, TMDS uses a twisted pair for noise reduction, rather than a coaxial cable that is conventional for carrying video signals. Similar to LVDS, data is transmitted serially over the data link. When transmitting video data, and using HDMI, three TMDS twisted pairs are used to transfer video data.

In such a system, each pixel packet is limited to 8 bits only. For bit depths higher than 8 bits, fragmented packs are used. This arrangement is no different than is already described in the current CTA-861 standard.

Based on CTA extension Version 3, identification of a six-primary color transmission would be performed by the sink device (e.g., the monitor). Adding recognition of the additional formats would be flagged in the CTA Data Block Extended Tag Codes (byte 3). Since codes 33 and above are reserved, any two bits could be used to identify that the format is RGB, RGBCYM, Y Cb Cr, or Y Cb Cr Cc Cy and/or identify System 1 or System 2. Should byte 3 define a six-primary sampling format, and where the block 5 extension identifies byte 1 as ITU-R BT.709, then logic assigns as 6P-B. However, should byte 4 bit 7 identify colorimetry as DCI-P3, the color gamut would be assigned as 6P-C.

FIG. 73 illustrates the current RGB sampling structure for 4:4:4 sampling video data transmission. For HDMI 4:4:4 sampling, video data is sent through three TMDS line pairs. FIG. 74 illustrates a six-primary color sampling structure, RGBCYM, using System 1 for 4:4:4 sampling video data transmission. FIG. 75 illustrates an example of System 2 to RGBCYM 4:4:4 transmission. FIG. 76 illustrates current Y Cb Cr 4:2:2 sampling transmission as non-constant luminance. FIG. 77 illustrates a six-primary color system (System 1) using Y Cr Cb Cc Cy 4:2:2 sampling transmission as non-constant luminance. FIG. 78 illustrates an example of a System 2 to Y Cr Cb Cc Cy 4:2:2 Transmission as non-constant luminance. FIG. 79 illustrates current Y Cb Cr 4:2:0 sampling transmission. FIG. 80 illustrates a six-primary color system (System 1) using Y Cr Cb Cc Cy 4:2:0 sampling transmission.

HDMI sampling systems include Extended Display Identification Data (EDID) metadata. EDID metadata describes the capabilities of a display device to a video source. The data format is defined by a standard published by the Video Electronics Standards Association (VESA). The EDID data structure includes, but is not limited to, manufacturer name and serial number, product type, phosphor or filter type, timings supported by the display, display size, luminance data, and/or pixel mapping data. The EDID data structure is modifiable and modification requires no additional hardware and/or tools.

EDID information is transmitted between the source device and the display through a display data channel (DDC), which is a collection of digital communication protocols created by VESA. With EDID providing the display information and DDC providing the link between the display and the source, the two accompanying standards enable an information exchange between the display and source.

In addition, VESA has assigned extensions for EDID. Such extensions include, but are not limited to, timing extensions (00), additional time data black (CEA EDID Timing Extension (02)), video timing block extensions (VTB-EXT (10)), EDID 2.0 extension (20), display information extension (DI-EXT (40)), localized string extension (LS-EXT (50)), microdisplay interface extension (MI-EXT (60)), display ID extension (70), display transfer characteristics data block (DTCDB (A7, AF, BF)), block map (F0), display device data block (DDDB (FF)), and/or extension defined by monitor manufacturer (FF).

In one embodiment, SDP parameters include data corresponding to a payload identification (ID) and/or EDID information.

Six-Primary Color System Display

FIG. 81 illustrates a dual stack LCD projection system for a six-primary color system. In one embodiment, the display is comprised of a dual stack of projectors. This display uses two projectors stacked on top of one another or placed side by side. Each projector is similar, with the only difference being the color filters in each unit. Refresh and pixel timings are synchronized, enabling a mechanical alignment between the two units so that each pixel overlays the same position between projector units. In one embodiment, the two projectors are Liquid-Crystal Display (LCD) projectors. In another embodiment, the two projectors are Digital Light Processing (DLP) projectors. In yet another embodiment, the two projectors are Liquid-Crystal on Silicon (LCOS) projectors. In yet another embodiment, the two projectors are Light-Emitting Diode (LED) projectors.

In one embodiment, the display is comprised of a single projector. A single projector six-primary color system requires the addition of a second cross block assembly for the additional colors. One embodiment of a single projector (e.g., single LCD projector) is shown in FIG. 82. A single projector six-primary color system includes a cyan dichroic mirror, an orange dichroic mirror, a blue dichroic mirror, a red dichroic mirror, and two additional standard mirrors. In one embodiment, the single projector six-primary color system includes at least six mirrors. In another embodiment, the single projector six-primary color system includes at least two cross block assembly units.

FIG. 83 illustrates a six-primary color system using a single projector and reciprocal mirrors. In one embodiment, the display is comprised of a single projector unit working in combination with at first set of at least six reciprocal mirrors, a second set of at least six reciprocal mirrors, and at least six LCD units. Light from at least one light source emits towards the first set of at least six reciprocal mirrors. The first set of at least six reciprocal mirrors reflects light towards at least one of the at least six LCD units. The at least six LCD units include, but are not limited to, a Green LCD, a Yellow LCD, a Cyan, LCD, a Red LCD, a Magenta LCD, and/or a Blue LCD. Output from each of the at least six LCDs is received by the second set of at least six reciprocal mirrors. Output from the second set of at least six reciprocal mirrors is sent to the single projector unit. Image data output by the single projector unit is output as a six-primary color system. In another embodiment, there are more than two sets of reciprocal mirrors. In another embodiment, more than one projector is used.

In another embodiment, the display is comprised of a dual stack Digital Micromirror Device (DMD) projector system. FIG. 84 illustrates one embodiment of a dual stack DMD projector system. In this system, two projectors are stacked on top of one another. In one embodiment, the dual stack DMD projector system uses a spinning wheel filter. In another embodiment, the dual stack DMD projector system uses phosphor technology. In one embodiment, the filter systems are illuminated by a xenon lamp. In another embodiment, the filter system uses a blue laser illuminator system. Filter systems in one projector are RGB, while the second projector uses a CYM filter set. The wheels for each projector unit are synchronized using at least one of an input video sync or a projector to projector sync, and timed so that the inverted colors are output of each projector at the same time.

In one embodiment, the projectors are phosphor wheel systems. A yellow phosphor wheel spins in time with a DMD imager to output sequential RG. The second projector is designed the same, but uses a cyan phosphor wheel. The output from this projector becomes sequential BG. Combined, the output of both projectors is YRGGCB. Magenta is developed by synchronizing the yellow and cyan wheels to overlap the flashing DMD.

In another embodiment, the display is a single DMD projector solution. A single DMD device is coupled with an RGB diode light source system. In one embodiment, the DMD projector uses LED diodes. In one embodiment, the DMD projector includes CYM diodes. In another embodiment, the DMD projector creates CYM primaries using a double flashing technique. FIG. 85 illustrates one embodiment of a single DMD projector solution.

FIG. 86 illustrates one embodiment of a six-primary color system using a white OLED display. In yet another embodiment, the display is a white OLED monitor. Current emissive monitor and/or television designs use a white emissive OLED array covered by a color filter. Changes to this type of display only require a change to pixel indexing and new six color primary filters. Different color filter arrays are used, placing each subpixel in a position that provides the least light restrictions, color accuracy, and off axis display.

FIG. 87 illustrates one embodiment of an optical filter array for a white OLED display.

FIG. 88 illustrates one embodiment of a matrix of an LCD drive for a six-primary color system with a backlight illuminated LCD monitor. In yet another embodiment, the display is a backlight illuminated LCD display. The design of an LCD display involves adding the CYM subpixels. Drives for these subpixels are similar to the RGB matrix drives. With the advent of 8K LCD televisions, it is technically feasible to change the matrix drive and optical filter and have a 4K six-primary color TV.

FIG. 89 illustrates one embodiment of an optical filter array for a six-primary color system with a backlight illuminated LCD monitor. The optical filter array includes the additional CYM subpixels.

In yet another embodiment, the display is a direct emissive assembled display. The design for a direct emissive assembled display includes a matrix of color emitters grouped as a six-color system. Individual channel inputs drive each Quantum Dot (QD) element illuminator and/or micro LED element.

FIG. 90 illustrates an array for a Quantum Dot (QD) display device.

FIG. 91 illustrates one embodiment of an array for a six-primary color system for use with a direct emissive assembled display.

FIG. 92 illustrates one embodiment of a six-primary color system in an emissive display that does not incorporate color filtered subpixels. For LCD and WOLED displays, this can be modified for a six-primary color system by expanding the RGB or WRGB filter arrangement to an RGBCYM matrix. For WRGB systems, the white subpixel could be removed as the luminance of the three additional primaries will replace it. SDI video is input through an SDI decoder. In one embodiment, the SDI decoder outputs to a Y CrCbCcCy-RGBCYM converter. The converter outputs RGBCYM data, with the luminance component (Y) subtracted. RGBCYM data is then converted to RGB data. This RGB data is sent to a scale sync generation component, receives adjustments to image controls, contrast, brightness, chroma, and saturation, is sent to a color correction component, and output to the display panel as LVDS data. In another embodiment the SDI decoder outputs to an SDI Y-R switch component. The SDI Y-R switch component outputs RGBCYM data. The RGBCYM data is sent to a scale sync generation component, receives adjustments to image controls, contrast, brightness, chroma, and saturation, is sent to a color correction component, and output to a display panel as LVDS data.

FIG. 106 is a schematic diagram of an embodiment of the invention illustrating a computer system, generally described as 800, having a network 810, a plurality of computing devices 820, 830, 840, a server 850, and a database 870.

The server 850 is constructed, configured, and coupled to enable communication over a network 810 with a plurality of computing devices 820, 830, 840. The server 850 includes a processing unit 851 with an operating system 852. The operating system 852 enables the server 850 to communicate through network 810 with the remote, distributed user devices. Database 870 may house an operating system 872, memory 874, and programs 876.

In one embodiment of the invention, the system 800 includes a network 810 for distributed communication via a wireless communication antenna 812 and processing by at least one mobile communication computing device 830. Alternatively, wireless and wired communication and connectivity between devices and components described herein include wireless network communication such as WI-FI, WORLDWIDE INTEROPERABILITY FOR MICROWAVE ACCESS (WIMAX), Radio Frequency (RF) communication including RF identification (RFID), NEAR FIELD COMMUNICATION (NFC), BLUETOOTH including BLUETOOTH LOW ENERGY (BLE), ZIGBEE, Infrared (IR) communication, cellular communication, satellite communication, Universal Serial Bus (USB), Ethernet communications, communication via fiber-optic cables, coaxial cables, twisted pair cables, and/or any other type of wireless or wired communication. In another embodiment of the invention, the system 800 is a virtualized computing system capable of executing any or all aspects of software and/or application components presented herein on the computing devices 820, 830, 840. In certain aspects, the computer system 800 may be implemented using hardware or a combination of software and hardware, either in a dedicated computing device, or integrated into another entity, or distributed across multiple entities or computing devices.

By way of example, and not limitation, the computing devices 820, 830, 840 are intended to represent various forms of electronic devices including at least a processor and a memory, such as a server, blade server, mainframe, mobile phone, personal digital assistant (PDA), smartphone, desktop computer, notebook computer, tablet computer, workstation, laptop, and other similar computing devices. The components shown here, their connections and relationships, and their functions, are meant to be exemplary only, and are not meant to limit implementations of the invention described and/or claimed in the present application.

In one embodiment, the computing device 820 includes components such as a processor 860, a system memory 862 having a random access memory (RAM) 864 and a read-only memory (ROM) 866, and a system bus 868 that couples the memory 862 to the processor 860. In another embodiment, the computing device 830 may additionally include components such as a storage device 890 for storing the operating system 892 and one or more application programs 894, a network interface unit 896, and/or an input/output controller 898. Each of the components may be coupled to each other through at least one bus 868. The input/output controller 898 may receive and process input from, or provide output to, a number of other devices 899, including, but not limited to, alphanumeric input devices, mice, electronic styluses, display units, touch screens, signal generation devices (e.g., speakers), or printers.

By way of example, and not limitation, the processor 860 may be a general-purpose microprocessor (e.g., a central processing unit (CPU)), a graphics processing unit (GPU), a microcontroller, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a state machine, gated or transistor logic, discrete hardware components, or any other suitable entity or combinations thereof that can perform calculations, process instructions for execution, and/or other manipulations of information.

In another implementation, shown as 840 in FIG. 106 multiple processors 860 and/or multiple buses 868 may be used, as appropriate, along with multiple memories 862 of multiple types (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core).

Also, multiple computing devices may be connected, with each device providing portions of the necessary operations (e.g., a server bank, a group of blade servers, or a multi-processor system). Alternatively, some steps or methods may be performed by circuitry that is specific to a given function.

According to various embodiments, the computer system 800 may operate in a networked environment using logical connections to local and/or remote computing devices 820, 830, 840 through a network 810. A computing device 830 may connect to a network 810 through a network interface unit 896 connected to a bus 868. Computing devices may communicate communication media through wired networks, direct-wired connections or wirelessly, such as acoustic, RF, or infrared, through an antenna 897 in communication with the network antenna 812 and the network interface unit 896, which may include digital signal processing circuitry when necessary. The network interface unit 896 may provide for communications under various modes or protocols.

In one or more exemplary aspects, the instructions may be implemented in hardware, software, firmware, or any combinations thereof. A computer readable medium may provide volatile or non-volatile storage for one or more sets of instructions, such as operating systems, data structures, program modules, applications, or other data embodying any one or more of the methodologies or functions described herein. The computer readable medium may include the memory 862, the processor 860, and/or the storage media 890 and may be a single medium or multiple media (e.g., a centralized or distributed computer system) that store the one or more sets of instructions 900. Non-transitory computer readable media includes all computer readable media, with the sole exception being a transitory, propagating signal per se. The instructions 900 may further be transmitted or received over the network 810 via the network interface unit 896 as communication media, which may include a modulated data signal such as a carrier wave or other transport mechanism and includes any deliver media. The term “modulated data signal” means a signal that has one or more of its characteristics changed or set in a manner as to encode information in the signal.

Storage devices 890 and memory 862 include, but are not limited to, volatile and non-volatile media such as cache, RAM, ROM, EPROM, EEPROM, FLASH memory, or other solid state memory technology, discs (e.g., digital versatile discs (DVD), HD-DVD, BLU-RAY, compact disc (CD), or CD-ROM) or other optical storage; magnetic cassettes, magnetic tape, magnetic disk storage, floppy disks, or other magnetic storage devices; or any other medium that can be used to store the computer readable instructions and which can be accessed by the computer system 800.

In one embodiment, the computer system 800 is within a cloud-based network. In one embodiment, the server 850 is a designated physical server for distributed computing devices 820, 830, and 840. In one embodiment, the server 850 is a cloud-based server platform. In one embodiment, the cloud-based server platform hosts serverless functions for distributed computing devices 820, 830, and 840.

In another embodiment, the computer system 800 is within an edge computing network. The server 850 is an edge server, and the database 870 is an edge database. The edge server 850 and the edge database 870 are part of an edge computing platform. In one embodiment, the edge server 850 and the edge database 870 are designated to distributed computing devices 820, 830, and 840. In one embodiment, the edge server 850 and the edge database 870 are not designated for computing devices 820, 830, and 840. The distributed computing devices 820, 830, and 840 are connected to an edge server in the edge computing network based on proximity, availability, latency, bandwidth, and/or other factors.

It is also contemplated that the computer system 800 may not include all of the components shown in FIG. 106 may include other components that are not explicitly shown in FIG. 106 or may utilize an architecture completely different than that shown in FIG. 106. The various illustrative logical blocks, modules, elements, circuits, and algorithms described in connection with the embodiments discussed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate the interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application (e.g., arranged in a different order or positioned in a different way), but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The above-mentioned examples are provided to serve the purpose of clarifying the aspects of the invention, and it will be apparent to one skilled in the art that they do not serve to limit the scope of the invention. By nature, this invention is highly adjustable, customizable and adaptable. The above-mentioned examples are just some of the many configurations that the mentioned components can take on. All modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the present invention. 

The invention claimed is:
 1. A system for displaying a multi-primary color system, comprising: a set of image data; an image data converter; a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable; and at least one display device; wherein the at least one display device and the image data converter are in network communication; wherein the image data converter is operable to map the set of image data to a color matrix, wherein the color matrix includes primary color values for Red (R), Green (G), Blue (B), Cyan (C), Yellow (Y), and Magenta (M); wherein the C, M, and Y primary color values are substantially equal in saturation to the R, G, and B primary color values, respectively; and wherein the image data converter is operable to convert the set of image data for display on the at least one display device using the color matrix.
 2. The system of claim 1, wherein the set of image data includes a bit level, wherein the image data converter is operable to convert the bit level of the set of image data, thereby creating an updated bit level.
 3. The system of claim 1, wherein once the set of image data has been converted by the image data converter for the at least one display device, the set of SDP parameters is modified based on the conversion.
 4. The system of claim 1, wherein the at least one display device is operable to display the multi-primary color system based on the set of image data.
 5. The system of claim 1, wherein the set of image data defines a minimum color luminance and a maximum color luminance.
 6. The system of claim 1, wherein the set of image data includes a first set of color channel data and a second set of color channel data.
 7. The system of claim 1, wherein the M primary color value is calculated based on values for R and B from the set of image data.
 8. The system of claim 1, wherein the image data converter includes a digital interface, wherein the digital interface is operable to encode and decode the set of image data.
 9. A system for displaying a multi-primary color system, comprising: a set of image data; an image data converter, wherein the image data converter includes a digital interface, wherein the digital interface is operable to encode and decode the set of image data; at least one transfer function (TF) for processing the set of image data; a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable; and at least one display device; wherein the at least one display device and the image data converter are in network communication; wherein the image data converter is operable to map the set of image data to a color matrix, wherein the color matrix includes primary color values for Red (R), Green (G), Blue (B), Cyan (C), Yellow (Y), and Magenta (M); wherein the C, M, and Y primary color values are substantially equal in saturation to the R, G, and B primary color values, respectively; and wherein the image data converter is operable to convert the set of image data for display on the at least one display device using the color matrix.
 10. The system of claim 9, wherein the set of SDP parameters indicate the set of image data being displayed on the at least one display device is using the multi-primary color system.
 11. The system of claim 9, wherein the at least one display device is operable to display the multi-primary color system based on the set of image data, and wherein the multi-primary color system displayed on the at least one display device is based on the set of image data.
 12. The system of claim 9, wherein the set of image data includes a bit level, wherein the image data converter is operable to convert the bit level for the set of image data to an updated bit level using the at least one TF.
 13. The system of claim 9, wherein the set of image data defines a minimum color luminance and a maximum color luminance.
 14. The system of claim 9, wherein the digital interface includes payload identification (ID) metadata, wherein the payload ID metadata is operable to identify the set of image data as a multi-primary color set of image data.
 15. The system of claim 9, wherein the M primary color value is calculated based on values for R and B from the set of image data.
 16. A system for displaying a multi-primary color system, comprising: a set of image data, wherein the set of image data includes a first set of color channel data and a second set of color channel data; an image data converter; at least one transfer function (TF) for processing the set of image data; a set of Session Description Protocol (SDP) parameters, wherein the set of SDP parameters is modifiable; and at least one display device; wherein the at least one display device and the image data converter are in network communication; wherein the image data converter is operable to map the set of image data to a color matrix, wherein the color matrix includes primary color values for Red (R), Green (G), Blue (B), Cyan (C), Yellow (Y), and Magenta (M); wherein the C, M, and Y primary color values are substantially equal in saturation to the R, G, and B primary color values, respectively; and wherein the image data converter is operable to convert the set of image data for display on the at least one display device using the color matrix.
 17. The system of claim 16, wherein the first set of color channel data defines a first minimum color luminance and a first maximum color luminance, wherein the second set of color channel data defines a second minimum color luminance and a second maximum color luminance.
 18. The system of claim 16, further including a set of saturation data corresponding to the set of image data, wherein the set of saturation data is used to extend a set of hue angles for the first set of color channel data and the second set of color channel data.
 19. The system of claim 16, wherein the set of SDP parameters includes the first set of color channel data, the second set of color channel data, mapping data for the set of image data, and a flag indicator.
 20. The system of claim 16, wherein the M primary color value is calculated based on values for R and B from the set of image data. 